I have a 6 station sprinkler system. I don't know the brand, the front
door cover is gone and I moved in two years ago. There are only 3
stations that actually are used. Station one will not stop watering
when station 2 and station 3 start to run. It actually runs while they
are on. It then shuts off.

Any suggestions on how to approach this situation?

I don't see a brand name anywhere. The control box is tan and brown.
There are 12 dials-- 6 for duration and 6 for days.