I opened this game's codes to know what's the cause of gallery problem.
The cause is, developer.
He's using 'action Replay()' to show gallery, and it demands proper using of 'renpy.end_replay()' in each scene.
Sadly, he didn't use 'renpy.end_replay()' in proper way. ...In almost scenes.
If he wanna fix that, he has to move almost 'renpy.end_replay()''s location and test them.
What a mess LOL
The cause is, developer.
He's using 'action Replay()' to show gallery, and it demands proper using of 'renpy.end_replay()' in each scene.
Sadly, he didn't use 'renpy.end_replay()' in proper way. ...In almost scenes.
If he wanna fix that, he has to move almost 'renpy.end_replay()''s location and test them.
What a mess LOL