Today I am driving to 3 and half hour, so far no drops.
Majored difference is that I am in my car and the phone is placed directly in front of AC vent. And is not hot.
This leading me think it is an overheating issue.
I will try to figure out the steps to make this situation reproducible on my phone.
PS. I have had my phone for ~2 years and it’s only the last month or so that this has been happening.