for me it was updating the firmware a 2nd time.  even though i was completely up to date w/firmware, when i recovered via Recovery Mode, H90 Edit said i needed to update the firmware.  my particular freeze-up kicked me back to the firmware version it shipped with.  Then, when updating to the first of five firmware versions, it locked up right after trying (1.1.4 i believe).  It did this 4 times, so on the 5th try i said “screw it” and started with the 2nd firmware update along with all the others sequentially until i was updated to the latest version.  It’s been about 4-5 days now, and no more freeze-ups.  I’ve also done a bunch of power cycles to keep pushing/testing it.  so far, so good.

to be clear, my lockups were happening upon power up though, not while attempting to manipulate knobs/settings, like the OP.