Unable to suppress Quart serving logs after Python 3.10 upgrade

Question

I'm moving a Quart webapp from python 3.7 to python 3.10 and I'm suddenly unable to suppress the server logs. Previously the advice from this thread:

getLogger('quart.serving').setLevel(ERROR)

and that's worked well for at least a year now. The only obvious change in my new deployment is Python 3.10; the same codebase and Quart version in Python 3.7 suppresses server logs just fine.

I've tried setting higher (CRITICAL) log levels, I tried using numbers to set it, and I verified that the logger had the correct effective level set getLogger('quart.serving').getEffectiveLevel(). Not sure what else to try.