I run my own mail server + spam filter, so I'll chime in. I have seen a high uptick in spam making it to my inbox in the last two weeks. I primarily rely on Spamhaus blocklists + a Bayesian filter trained on old spam.

The uptick I have seen is going from 0-2 spams making it to my inbox to 10-20 spams making it to my inbox. When this has happened in the past, I have assumed it is spammers bypassing blocklists by finding new hosts, or by spammers finding a clever way to beat the filter. Usually after these big upticks, they drop off again suddenly, which makes me believe that it was a blocklist bypass and not a filter bypass (my filter is pretty weak and hasn't been retrained/updated in many years.)