We wrote a troubleshooting manual that is there to help users with cases like these. Did you read it?
There’s a special section there that explain exactly what you have to do in case of stuck update or if you want to manually update.
Re-flashing the mSD card is also an option, user data will not be erased, no worry, all data is on SSD. But also could be some other components stuck so see the manual about that.
First, yes try re-flashing.