I have also had the identical intermittent electric trim experiences. But my plane is a Lancair Columbia 300 .
This has been a very stubborn problem, yet to be corrected, and I’m intrigued by the possibility of it’s being from a source common to both planes.
My first failure was on my first landing as I flew away from the factory upon completion of delivery. My last failure was on my last flight. There have been extensive periods of trouble free flight as well as extensive periods of fairly consistent failure during the intervening 122 hours.
Substantial work to correct my autopilot/trim problems has been performed both by Lancair and STec. I must say they have been very supportive but an intermittent trim problem persists.
The SR20 has one pitch servo. The SR22 has two, one that responds to “manual” input from the pilot and another that is dedicated to the autopilot. In your postings it will be helpful to know which plane you are flying.
My system is like the SR22. I have found I am able to restore manual trim by momentarily engaging the autopilot VS. This can be important to know if manual trim failure is compounded by runaway trim, as mine was in the early failures.
I think mutual benefit may be gained from discussion of mutual failures of the same systems, hence this post.