I have been having the same issue.
I have opened the savefile using "Ren'py Save Editor" and searched for variable "dyder_camp". It found it twice: one set at true and the other at false. I had to fix it by setting the other at True too.
Pridefall was 3 and the day was like 70 days higher than dayflag_pridefall.
After a long, lovely conversation on the Ren'py Discord...
1. There can't be two variables with the same name. The save file editor you are using is... weird. There
is an issue with code from using older saves from previous versions being read by save files multiple times due to where it is/was placed in the code. As I have stated everywhere this game is posted...
you should start with a new save file. I know, it sucks. It's a long game. I'm new to this, though, and a lot of things change between versions to streamline things and make them run better from the beginning. Not in the middle. However, this really doesn't matter because...
2. The "true" value of every variable (not True/False, but true as in what it should be) is loaded by the save file. Even if I had made corrections to the code, it wouldn't change the value in your save file. Long, long explanation available if you want. It's sleep-inducing. The error is fixed with the 0.5.1a patch. This is a known error and prompted the quick update. Be sure you are running 0.5.1a PE version, not the 0.5.1 PE.
3. You still did the right thing, more or less. Without the 0.5.1a PE update, the variable would never have changed. I still have no idea why. Again, new to this whole "coding thing."
4. The save editor you're using doesn't correctly tag certain variables. For example "copper" is the variable used to denote silver owned in the game (don't ask). However, the save editor lists it as a boolean value of True.
*shrug*
Anyway, if you need any further assistance, I'll be back in a few hours.