Actions are being deleted

As for why this happens in the first place - I'd first look at folder permissions. It sounds like Photoshop may not have full privileges to your user account, so it can't write preferences normally at shutdown.

It could also be irregular shutdowns, effectively, the application crashing at shutdown instead of exiting normally. That would also prevent the preference file from being written correctly.

https://prepression.blogspot.com/2017/01/photoshop-custom-action-file-backup.html

One should manually save out each action set "folder" individually to a .atn file using the menu on the upper right of the action panel window.

Loaded .atn files or newly created and unsaved action sets are temporarily stored in the Actions Palette presets file (Actions Palette.psp). This file should be considered temporary and may be subject to corruption or loss, which is why making an explicit save to .atn file for each individual action set is strongly advised.

Never save custom actions inside the Default Actions set (folder), as this file is reloaded into Photoshop when the "Reset Actions" command is used and your custom actions will be lost.