For everyone having issues with gallery unlocks, just start a new game. You'll get the option to "Start from New Content" and can set who took your virginity as well as whether Emma is your girlfriend or not. The last option gives you the ability to unlock all previous gallery scenes so the only new scenes you'll have locked are the new ones. The only stats you lose are who you had your first blowjob from, who you ate out first, etc. The only stat you can adjust is who took your V-card.
To get the new scenes you just need Emma to be your girlfriend and wait until night where she'll visit you and a follow-up morning scene with her. There is also a scene with Berry and a new character who visits the Front Yard around 2:00 pm.
For those looking for the last 3 scenes in the "Multi and others" category of the gallery, those three require Emma to not be your girlfriend. You'll lose access to the repeatable Emma night/morning scene but now when the new character visits you'll have sex with her instead of just Berry. This involves 3 scenes with her which are the missing 3.
In short:
Start a new game > Skip to new content > Emma Girlfriend > Unlock Gallery > Emma Night/Morning Scene + Berry Front Yard 2:00 pm scene
Start a new game > Skip to new content > Emma not Girlfriend > Unlock Gallery > New Character Front Yard 2:00 pm scenes.