Thanks tomt for the update!
The instructions/ code I posted earlier were referring to this version of caffeine [2. 8]. Otherwise there wouldn't be the caffeine-indicator command available

Not sure - if it will correct your issue 100% - but a few other applications to check settings on:
Power Manager - make sure that you dont have a sleep or shut down monitor - think mine had something by default
Also Light-Locker usually for screen lock, but also screensaver functionality.
For me - I had wake from hibernate issues - ScreenSaver and Power Manger are similarly based..
I disabled Light-Locker completely
Hello!
There are some tricks to installing and using Caffeine - like changing the name in the .desktop file to load it as caffeine-indicator, changing the supplied icons for darker themes if necessary, etc.
Duckeenie recently posted this script that looks like it'd take a whole lot less code to implement than Caffeine:
https://www.linuxliteos.com/forums/scrip.../#msg18277
Next chance I get, I'll try this one out for myself...
73 DE N4RPS
Rob