94 Trooper Right Turn Signal

I have a 1994 Isuzu Trooper. A few months ago, when I turned on the right turn signal I got an annoying buzzing sound and the inside indicator light, as well as outside right front and back turn lights did not work. All lights for the left turn were OK. I felt under the dash and put my fingers on the flasher and felt it vibrating when I heard the buzzing. After a few days it went away and all was right with the world. It returned a few times since then and then went away each time. I recently bought a new flasher (not factory replacement grade) and took the Trooper to a mechanic. They said a couple of bulbs were out and they replaced them, plus put the new flasher in. All Good. I took the car home and put in the old flasher and everything was still good - for a while. Now, right turn does not work with either flasher. “New” flasher does not buzz, old one still does. With the new one I hear it clicking but no inside indicator light. All 4 outside lights flash when emergency flasher is turned on. Can anyone tell me what is going on!?