Import maps brokes after branching from main that uses import maps

[AikePetunia]

Hi! I found this bug and it's really easy to replicate.

1. use import maps feature on a main branch
2. Create a checkpoint and branch from there.
3. change to branch
4. press play -> all import maps reference are broken, even if it still detected from config, also if u delete the past import map and try to add a new one, stills broken.