Computer immediately wakes after suspending, without input

Please read this:

Then try with 2 LTS kernels.

Please read this

Do both of the above and see if the problem goes away automagically. :grin:

:crossed_fingers:

P.S. Some applications can inhibit sleep state. Spotify is the most notorious one as you cannot turn it off, but VLC, qBittorrent, … can be set to inhibit sleep too.