First you might want to update your navidrome to a recent version they added a ton of things that improve many areas for Symfonium.
The only thing I see in those logs is the auto offline on the last played playlist that triggers too much work that I can optimize, but you probably want to switch to the new rolling cache with playback automatic offline mode to simplify this anyway.
The logs does not show the app doing anything, I see you just updated to 9.1.0 but that would not explain the graph it just take some ressources during the update to migrate the db.
There’s no playback or anything.
Are you casting and connected to a remote player ?
I do not see anything special, one possible cause would be that you are far from the wifi access and the network access require full power and use the battery.
You can workaround that with playback cache and pre caching, this will use wifi a lot less and can help.
Else try to uncheck the prefer internal decoder option in the settings in case the files triggers a bug in ffmpeg using too much cpu.