In the prison on the conquest route, some of the shower images are grey with "bg the prizec2", and after the achievement unlocked image stays on the top left corner until the Advance option is chosen.
Also when Red gets possessed there are a few images where MC's red conquest route appearance gets swapped with the blue good route appearance.
Viewing post in BUG REPORT THREAD
Here's the save where it occurs if you have time to look into it.
https://www.mediafire.com/file/c2j1y5k7lorl3ri/9-2-LT1.save/file