I do face the same problem but none of the recommended solutions did help me to access my synology shares.
It still does show a grey point in the unassigned devices overview and in the log it shows up:
Aug 26 11:12:09 UNRAIDHOME unassigned.devices: Remote SMB/NFS server '192.168.1.22' is offline and share '//192.168.1.22/media' cannot be mounted.
Aug 26 11:12:09 UNRAIDHOME unassigned.devices: Remote SMB/NFS server '192.168.1.22' is offline and share '//192.168.1.22/software' cannot be mounted.
I can access this shares from any other device (windows & Linux pop_os) using the same user I created new in synology.
Any further recommendation would be helpfull, I'm running out of ideas.