Server becomes unresponsive (except for VM!) 3-4 minutes after boot. Only hard-reset works.

Hi.

Today my server is acting weirdt-tower-diagnostics-20230404-2115.zip. After a few minutes of uptime, the shares become inaccessible, and so does the GUI of the server. The docker containers are also not working. My VM running on the server is working fine, except I can't open any shares, obviously. I'm writing this from the VM now. Diagnostics attached. The diagnostics are taken from the web GUI before it becomes unresponsive. Afterwards, I can SSH into the server and start the diagnostics command, however, it just says "Starting diagnostics collection ..." and the cursor blinks in a loop. Here is from the log file after successful startup. Errors start popping up about 15 minutes after startup (scroll down).

Please, if anyone has a clue to what's going on... 

Apr  4 21:14:45 T-TOWER  avahi-daemon[27824]: Registering new address record for 127.0.0.1 on lo.IPv4.
Apr  4 21:14:45 T-TOWER  emhttpd: shcmd (162): /etc/rc.d/rc.avahidnsconfd restart
Apr  4 21:14:45 T-TOWER root: Stopping Avahi mDNS/DNS-SD DNS Server Configuration Daemon: stopped
Apr  4 21:14:45 T-TOWER root: Starting Avahi mDNS/DNS-SD DNS Server Configuration Daemon:  /usr/sbin/avahi-dnsconfd -D
Apr  4 21:14:45 T-TOWER  avahi-dnsconfd[27833]: Successfully connected to Avahi daemon.
Apr  4 21:14:46 T-TOWER  avahi-daemon[27824]: Server startup complete. Host name is T-TOWER.local. Local service cookie is 2480387511.
Apr  4 21:14:46 T-TOWER  avahi-daemon[27824]: Service "T-TOWER" (/services/ssh.service) successfully established.
Apr  4 21:14:46 T-TOWER  avahi-daemon[27824]: Service "T-TOWER" (/services/smb.service) successfully established.
Apr  4 21:14:46 T-TOWER  avahi-daemon[27824]: Service "T-TOWER" (/services/sftp-ssh.service) successfully established.
Apr  4 21:15:07 T-TOWER  nmbd[27788]: [2023/04/04 21:15:07.567216,  0] ../../source3/nmbd/nmbd_become_lmb.c:398(become_local_master_stage2)
Apr  4 21:15:07 T-TOWER  nmbd[27788]:   *****
Apr  4 21:15:07 T-TOWER  nmbd[27788]:   
Apr  4 21:15:07 T-TOWER  nmbd[27788]:   Samba name server T-TOWER is now a local master browser for workgroup WORKGROUP on subnet 172.17.0.1
Apr  4 21:15:07 T-TOWER  nmbd[27788]:   
Apr  4 21:15:07 T-TOWER  nmbd[27788]:   *****
Apr  4 21:15:07 T-TOWER  nmbd[27788]: [2023/04/04 21:15:07.567390,  0] ../../source3/nmbd/nmbd_become_lmb.c:398(become_local_master_stage2)
Apr  4 21:15:07 T-TOWER  nmbd[27788]:   *****
Apr  4 21:15:07 T-TOWER  nmbd[27788]:   
Apr  4 21:15:07 T-TOWER  nmbd[27788]:   Samba name server T-TOWER is now a local master browser for workgroup WORKGROUP on subnet 172.18.0.1
Apr  4 21:15:07 T-TOWER  nmbd[27788]:   
Apr  4 21:15:07 T-TOWER  nmbd[27788]:   *****
Apr  4 21:15:07 T-TOWER  nmbd[27788]: [2023/04/04 21:15:07.567458,  0] ../../source3/nmbd/nmbd_become_lmb.c:398(become_local_master_stage2)
Apr  4 21:15:07 T-TOWER  nmbd[27788]:   *****
Apr  4 21:15:07 T-TOWER  nmbd[27788]:   
Apr  4 21:15:07 T-TOWER  nmbd[27788]:   Samba name server T-TOWER is now a local master browser for workgroup WORKGROUP on subnet 192.168.122.1
Apr  4 21:15:07 T-TOWER  nmbd[27788]:   
Apr  4 21:15:07 T-TOWER  nmbd[27788]:   *****
Apr  4 21:15:07 T-TOWER  nmbd[27788]: [2023/04/04 21:15:07.567521,  0] ../../source3/nmbd/nmbd_become_lmb.c:398(become_local_master_stage2)
Apr  4 21:15:07 T-TOWER  nmbd[27788]:   *****
Apr  4 21:15:07 T-TOWER  nmbd[27788]:   
Apr  4 21:15:07 T-TOWER  nmbd[27788]:   Samba name server T-TOWER is now a local master browser for workgroup WORKGROUP on subnet 10.10.100.10
Apr  4 21:15:07 T-TOWER  nmbd[27788]:   
Apr  4 21:15:07 T-TOWER  nmbd[27788]:   *****

And now, almost 15 minutes later, this happens (see below). 10.10.100.10 is my server, 10.10.100.139 is my VM. Something's happening with the unnassigned devices? 

Apr  4 21:29:46 T-TOWER nginx: 2023/04/04 21:29:46 [error] 9252#9252: *263 upstream timed out (110: Connection timed out) while reading response header from upstream, client: 10.10.100.139, server: , request: "POST /plugins/unassigned.devices.preclear/Preclear.php HTTP/2.0", subrequest: "/auth-request.php", upstream: "fastcgi://unix:/var/run/php5-fpm.sock", host: "10.10.100.10", referrer: "https://10.10.100.10/Docker"
Apr  4 21:29:46 T-TOWER nginx: 2023/04/04 21:29:46 [error] 9252#9252: *263 auth request unexpected status: 504 while sending to client, client: 10.10.100.139, server: , request: "POST /plugins/unassigned.devices.preclear/Preclear.php HTTP/2.0", host: "10.10.100.10", referrer: "https://10.10.100.10/Docker"
Apr  4 21:29:50 T-TOWER nginx: 2023/04/04 21:29:50 [error] 9252#9252: *263 upstream timed out (110: Connection timed out) while reading response header from upstream, client: 10.10.100.139, server: , request: "POST /plugins/unassigned.devices.preclear/Preclear.php HTTP/2.0", subrequest: "/auth-request.php", upstream: "fastcgi://unix:/var/run/php5-fpm.sock", host: "10.10.100.10", referrer: "https://10.10.100.10/Tools/Syslog"
Apr  4 21:29:50 T-TOWER nginx: 2023/04/04 21:29:50 [error] 9252#9252: *263 auth request unexpected status: 504 while sending to client, client: 10.10.100.139, server: , request: "POST /plugins/unassigned.devices.preclear/Preclear.php HTTP/2.0", host: "10.10.100.10", referrer: "https://10.10.100.10/Tools/Syslog"

Apr  4 21:32:56 T-TOWER nginx: 2023/04/04 21:32:56 [error] 9252#9252: *263 upstream timed out (110: Connection timed out) while reading response header from upstream, client: 10.10.100.139, server: , request: "GET /Settings HTTP/2.0", subrequest: "/auth-request.php", upstream: "fastcgi://unix:/var/run/php5-fpm.sock", host: "10.10.100.10", referrer: "https://10.10.100.10/Docker"
Apr  4 21:32:56 T-TOWER nginx: 2023/04/04 21:32:56 [error] 9252#9252: *263 auth request unexpected status: 504 while sending to client, client: 10.10.100.139, server: , request: "GET /Settings HTTP/2.0", host: "10.10.100.10", referrer: "https://10.10.100.10/Docker"

Apr  4 21:35:34 T-TOWER nginx: 2023/04/04 21:35:34 [error] 9252#9252: *263 upstream timed out (110: Connection timed out) while reading response header from upstream, client: 10.10.100.139, server: , request: "GET /Dashboard HTTP/2.0", subrequest: "/auth-request.php", upstream: "fastcgi://unix:/var/run/php5-fpm.sock", host: "10.10.100.10", referrer: "https://10.10.100.10/Tools/Syslog"
Apr  4 21:35:34 T-TOWER nginx: 2023/04/04 21:35:34 [error] 9252#9252: *263 auth request unexpected status: 504 while sending to client, client: 10.10.100.139, server: , request: "GET /Dashboard HTTP/2.0", host: "10.10.100.10", referrer: "https://10.10.100.10/Tools/Syslog"
Apr  4 21:36:39 T-TOWER nginx: 2023/04/04 21:36:39 [crit] 9252#9252: *11657 SSL_do_handshake() failed (SSL: error:141CF06C:SSL routines:tls_parse_ctos_key_share:bad key share) while SSL handshaking, client: 168.80.174.2, server: 0.0.0.0:443

Edited April 4, 20233 yr by mrtrilby
Added to log