Android Studio imports randomly stopped working and after a while started working again out of nowhewre

Question

We are a robotics team in First Tech Challenge, we were working on a roadrunner 1.0 implementation. Our import statements stopped working all of a sudden and randomly, 7 hours later, they started working again, we were wondering what king of circumstances could lead to such behavior.

We were using a lot of imports and we had like 200 import errors. We are using the latest Android studio Jellyfish.

The issue randomly fixed itself, but we are still dumbfounded as to what could cause this.