My plex media server installation is on a WD MyCloud EX2 Ultra NAS device.
Some of my tracks have sonic analysis completed and a lot of them dont.
I have folowed the online instructions to activate sonic analysis but i do not see the check box to activate Sonic Analysis in the server settings advanced page.
As i can see the soundwave representation on some tracks, and i get the cool transitions from one track to the next. Others have only a flat progress bar and no cool transitions.
Sonic analysis is a whole different thing. Sonic analysis is not available on ARM, but loudness analysis is.
As to why it always gets stuck, you need to find out by inspecting the log files.
It can also help to look into the /tmp folder of your system during, or immediately after the server maintenance period.
Keeping the server running and able to access the media files during this maintenance period is also necessary.
You should be able to find out the album(s) where the analysis is failing for some reason.
Do you have some albums which have an excessive amount of tracks? (i.e. box sets)
These require a large storage space in the /tmp folder. If you are running in a VM or on some embedded device, you might not have that much free space.
You could try to temporarily remove those albums from the library. Then see if the loudness analysis is progressing further.