Found a WordPress alternative, ClassicPress, a fork of WordPress.
Apparently Simply Static doesn’t work with it, or you have to figure out which version of Simply Static works with it.
I just compiled WP2Static instead of trying to fix Simply Static anymore.
Had to rollback openSUSE on my Steam Deck, now Slowroll is broken too when updating. I’m not leaving receiver and/or TV on 24/7. I do want sound when the receiver turns on though. Not even using HDMI for sound.
Staatic works too. It’s possible a ClassicPress update, could cause WP2Static to stop working.