Noticed the GUI was acting pretty slow all of a sudden and when that happened could see spikes in both CPU usage and Network Traffic. Like on Network it'd spike in the graph to like 9Gbps. 

 

Then noticed this in syslog:

 

Mar  6 14:45:33 AWE php-fpm[5787]: [WARNING] [pool www] child 32093 exited on signal 9 (SIGKILL) after 29.731827 seconds from start
Mar  6 14:45:35 AWE php-fpm[5787]: [WARNING] [pool www] child 32119 exited on signal 9 (SIGKILL) after 31.650279 seconds from start
Mar  6 14:45:48 AWE autofan: Highest disk temp is 38C, adjusting fan speed from: 61 (23% @ 747rpm) to: 48 (18% @ 843rpm)
Mar  6 14:47:33 AWE php-fpm[5787]: [WARNING] [pool www] child 962 exited on signal 9 (SIGKILL) after 142.656216 seconds from start
Mar  6 14:47:47 AWE php-fpm[5787]: [WARNING] [pool www] child 14354 exited on signal 9 (SIGKILL) after 134.597951 seconds from start
Mar  6 14:47:54 AWE autofan: Highest disk temp is 39C, adjusting fan speed from: 48 (18% @ 767rpm) to: 61 (23% @ 994rpm)
Mar  6 14:48:03 AWE php-fpm[5787]: [WARNING] [pool www] child 14423 exited on signal 9 (SIGKILL) after 148.214152 seconds from start
Mar  6 14:48:17 AWE php-fpm[5787]: [WARNING] [pool www] child 22996 exited on signal 9 (SIGKILL) after 136.367080 seconds from start
Mar  6 14:48:28 AWE php-fpm[5787]: [WARNING] [pool www] child 28825 exited on signal 9 (SIGKILL) after 55.399195 seconds from start
Mar  6 14:48:30 AWE php-fpm[5787]: [WARNING] [pool www] child 30196 exited on signal 9 (SIGKILL) after 42.653882 seconds from start
Mar  6 14:48:32 AWE php-fpm[5787]: [WARNING] [pool www] child 11231 exited on signal 9 (SIGKILL) after 29.004422 seconds from start
Mar  6 14:49:03 AWE emhttpd: read SMART /dev/sdc
Mar  6 14:49:48 AWE php-fpm[5787]: [WARNING] [pool www] child 22342 exited on signal 9 (SIGKILL) after 11.804580 seconds from start
Mar  6 14:50:50 AWE php-fpm[5787]: [WARNING] [pool www] child 14086 exited on signal 9 (SIGKILL) after 13.963540 seconds from start
Mar  6 14:51:02 AWE php-fpm[5787]: [WARNING] [pool www] child 16151 exited on signal 9 (SIGKILL) after 11.765929 seconds from start
Mar  6 14:51:17 AWE php-fpm[5787]: [WARNING] [pool www] child 23223 exited on signal 9 (SIGKILL) after 14.522135 seconds from start
Mar  6 14:51:30 AWE php-fpm[5787]: [WARNING] [pool www] child 27840 exited on signal 9 (SIGKILL) after 13.452030 seconds from start
Mar  6 14:51:53 AWE php-fpm[5787]: [WARNING] [pool www] child 29927 exited on signal 9 (SIGKILL) after 23.079546 seconds from start
Mar  6 14:51:55 AWE php-fpm[5787]: [WARNING] [pool www] child 31491 exited on signal 9 (SIGKILL) after 18.646314 seconds from start
Mar  6 14:52:53 AWE php-fpm[5787]: [WARNING] [pool www] child 21706 exited on signal 9 (SIGKILL) after 16.526706 seconds from start
Mar  6 14:53:10 AWE php-fpm[5787]: [WARNING] [pool www] child 30773 exited on signal 9 (SIGKILL) after 17.691974 seconds from start
Mar  6 14:53:52 AWE php-fpm[5787]: [WARNING] [pool www] child 12465 exited on signal 9 (SIGKILL) after 15.938438 seconds from start
Mar  6 14:53:54 AWE php-fpm[5787]: [WARNING] [pool www] child 12466 exited on signal 9 (SIGKILL) after 17.986666 seconds from start
Mar  6 14:54:04 AWE php-fpm[5787]: [WARNING] [pool www] child 18259 exited on signal 9 (SIGKILL) after 12.182820 seconds from start
Mar  6 14:54:16 AWE php-fpm[5787]: [WARNING] [pool www] child 24514 exited on signal 9 (SIGKILL) after 12.084464 seconds from start
Mar  6 14:56:54 AWE php-fpm[5787]: [WARNING] [pool www] child 13701 exited on signal 9 (SIGKILL) after 126.667100 seconds from start
Mar  6 14:57:27 AWE php-fpm[5787]: [WARNING] [pool www] child 704 exited on signal 9 (SIGKILL) after 125.478612 seconds from start
Mar  6 15:02:56 AWE php-fpm[5787]: [WARNING] [pool www] child 26454 exited on signal 9 (SIGKILL) after 19.910296 seconds from start
Mar  6 15:05:05 AWE php-fpm[5787]: [WARNING] [pool www] child 7769 exited on signal 9 (SIGKILL) after 111.660475 seconds from start
Mar  6 15:05:22 AWE winbindd[16541]: [2024/03/06 15:05:21.985600,  0] ../../source3/winbindd/winbindd_samr.c:71(open_internal_samr_conn)
Mar  6 15:05:22 AWE winbindd[16541]:   open_internal_samr_conn: Could not connect to samr pipe: NT_STATUS_CONNECTION_DISCONNECTED
Mar  6 15:05:41 AWE php-fpm[5787]: [WARNING] [pool www] child 8305 exited on signal 9 (SIGKILL) after 139.216771 seconds from start
Mar  6 15:05:43 AWE php-fpm[5787]: [WARNING] [pool www] child 10079 exited on signal 9 (SIGKILL) after 59.938068 seconds from start
Mar  6 15:05:54 AWE php-fpm[5787]: [WARNING] [pool www] child 8097 exited on signal 9 (SIGKILL) after 30.222862 seconds from start
Mar  6 15:05:57 AWE php-fpm[5787]: [WARNING] [pool www] child 14347 exited on signal 9 (SIGKILL) after 13.291311 seconds from start

 

Any idea what could be causing this all of a sudden? 

Try booting in safe mode and/or closing any browser windows open to the GUI, only open when you need to use it then close again.