Sometimes a test scenario will work, then it won't for no reason

I'm not sure how I can phrase this, but it legit would work one day, then if I open it up the next it may not work. It happens once in awhile, but its enough where its starting to get annoying. The logs usually say things like there was an interruption during the test. Like just general things, and like I easily fix this sometimes but just closing the testing scenario and reopening it.