AirPods disconnect when I turn off my Apple Watch timer.

I use my Apple Watch to time my rests between sets at the gym while listening to music or podcasts through my AirPods, and whenever the timer goes off on my watch and I stop it, one of several things happens:

1) The audio stops, and when I manually resume it, it plays through my phone speakers instead of my AirPods

2) The audio automatically resumes through my phone speakers instead of my AirPods

3) The audio has to be manually restarted but correctly resumes through the AirPods

4) The audio automatically resumes through my AirPods (how it should happen)

There is no rhyme or reason to which of these four things will happen every time the timer goes off, and it’s pretty annoying to have to sort it out every other minute at the gym. I would’ve thought that since I’m using all Apple products, this wouldn’t happen.