Sorry that I have to object, but I‘m sure this is not true at all.
Of course it can absolutely be a problem with the operating system, even if the majority is not encountering it.
The vast majority of OS problems occur only within certain configurations and not for everyone. Just have a look around here in these forums and read some of the older complaints which were doubtlessly caused by the OS only (a good proof of this is if the problem has been fixed by an OS update later on) - you will find statements of people not having that specific problem in almost every case.
Others not having the same problem never proofs anything at all. It can just be an indication for the true nature of the problem and its root causes.
In this specific case, many people having problems just since they upgraded to watchOS 7 and at the same time almost no one complaining about similar issues suddenly occurring on watchOS 6.2.8 or older doesn‘t really point towards 3rd party software or configuration issues - or what else is your conclusion?
In terms of possible workarounds for this problem, it would nevertheless be interesting to know more about the circumstances which make it occur - and which maybe help to make it (at least temporarily) disappear until the bug has been fixed.