I can't edit saves so you clearly put some anti-cheat in the game, neither can I use urm....
In any case after playing the last update it seems to me like you lied about this game not having ntr, sharing in the future, the last update ends with some dude coming home with the mom.... and Mariya talking with him half naked....
I know what kind of devs put this shit in their story and all those devs make cuck games... so will just ignore this from now on, seems pretty clear what kind of content will be soon in the game.
And just to be clear, anyone else (not the mc) fucking 1 of the lis (love interest) is cuck shit ntr.
Then explain that blonde guy sleeping in the house of the mc after coming home with the mom?
you are basically teasing it in the last update cliffhanger.
And the anti-cheating you must know what it is because you added the code yourself, if someone edits the save the game doesn't allow the player to continue with that save.
I can't be sure, but you've probably faced with the new security system in Ren'Py that prevents players from loading potentially harmful save files: https://github.com/renpy/renpy/issues/4879