I have also one Wrover B module chip rev 1 with same behavior. Board is a custom design and idf version is 3.3 10 boards have been tested extensively and one have started failing after months of use. It usually fails after flashing. It seems that heat has some effect, since the failure usually disap...

I also had a similar problem while driving SK6812 leds with the RMT interface. Root cause for me was that the dynamic frequency scaling being set from 40MHz to 160MHz while RMT was attended to use 80MHz APB clock. When CPU clock dropped to 40MHz the automatic APB divider could not keep up and RMT re...