Sorry for all this. We seem to go months in good control, we learn to relax a bit, and then another change is imposed on us and we commence the journey of disruption and arrhythmia all over again. It's frustrating.

I can only guess, but is sounds like your issue is a loss of tone of the Vagus nerve.
https://pmc.ncbi.nlm.nih.gov/articles/PMC7533130/
As inexpert as I am, and please bear this in mind as you read, I think you should see an electrophysiologist (EP) and get an assessment. They perform catheter ablations and can isolate places in your heart where extra beat signals enter the lining of the four pumps and cause them to contract out of sequence...out of rhythm.

I was most symptomatic during the day when my mind was active, or when I bent over to tie my shoes when I was heavy with visceral fat. Or, some find alcohol, red wine, caffeine, some medications, even worry over anything that presents a problem in life...they can all bring on arrhythmias. So can low systemic magnesium levels, a chronic condition in the western world. On the other hand, my sister-in-law has all her arrhythmia at night when she climbs into bed and tries to fall asleep. Puzzling, but I'm so thankful not to be affected that way.

Please see a good cardiologist for a formal assessment, or have that person refer you to an EP.