Try lowering the RAM cache size, you can do that with the tips and tweaks plugin, using a disk share instead of user share whenever possible should also help.
Share cache full doesn't mean cache is full, that will be logged as "cache disk full", share cache full means a share is hitting the minimum free space set and it's now copying directly to the array.
Make sure there's nothing open on a disk, ssh session will be enough.
This usually means the same devices are being detected twice, make sure there's only one cable from the HBA to the NetApp enclosure, Unraid doesn't support SAS multipath.
Yes, thank you @Altwazar, everyone having this specific call trace with Unraid is using Qbittorrent or is there anyone not using it and still having this issue?
Yes, you need a file sync tool, like Syncback free, or if the D drives on the PCs are shared over SMB you can have for example an rsync script on Unraid doing the sync.
Make sure there's no Android device with a browser window opened on the WebGUI, it can cause issues when the device is sleeping, and to clear the log you can reboot.
You basically just send an email describing the problem with the log, before doing it I would recommend running a file system check directly on the disk to rule out any md driver issues, unlikely it will make a difference but better to be sure
xfs_repair -v /dev/sdX1
Replace X with the correct disk letter and note the 1 in the end.