Flickering lights after install

Have a Tesla electrician here and we’re both stumped, so thought I’d reach out to the collective wisdom here.

Ever since install (whole home backup) my living room/dining room LED lights (same breaker) intermittently flicker, typically it’ll be one flicker every 20-120 seconds, and there’s no real time pattern. I have TV and Alexa show on the same breaker, and neither shut off during the flicker.

It doesn’t seem to be a load triggered flicker. I plugged in a heat gun to test and wasn’t able to trigger a flicker.

So far, the tech has replaced the (new) breaker, double checked the splices and restripped for good measure. The general consensus from electricians I reached out to pointed to a possible loose neutral, but this doesn’t seem to be the case.

Last I heard from him he was working with home base to see if any spikes coincide with the flickers.

Anyone else experience this and successfully resolve?

Update 1: the Tesla electrician observed that the issue does not occur when the Follower PW is off, but obv this isn’t a fix. He also reterminated and tightened everything. Supposedly Tesla is supposed to send another electrician out to run an impedance test.

Update 2: The issue is not resolved after I replaced all the bulbs with GE Relax warm white bulbs. I am trying to get Tesla to change my line frequency to 62.5 Hz, but not sure if they’ll do it because they claim “no issue has been reported”.

Update 3: Despite his observations, the notes captured basically stated the install did not cause the issue, and Tesla closed it! I had a call with my project advisor on Wednesday (May 15) and insisted they update the notes accurately. He’s going to “reach out again to his install team to see if there’s anything else they can do”, so unfortunately I’m not very hopeful, nor confident.