Yeah I got an old mower from the 1970s and it's better made than any of the crap they make now but it's almost impossible to find parts and the guy at the shop says he doesn't care...
You might have gotten a bad RE firmware update and your RE may be bricked (i.e. ruined). The good news is, you can probably find another RE on eBay for around $50 which will solve your problem. My understanding is that DJI has fixed that update problem but has not found a way to fix the bricked extenders.
Let's get
@J Dot's advice...