Series X suddenly stopped recognizing any controller — looking for ideas

My Series X suddenly stopped connecting to my controller about a month ago, and I've tried pretty much everything I can think of.

The controller:

• Works immediately when plugged into my PC with the same Anker cable.
• Won't connect wirelessly to the Xbox.
• Won't work wired to the Xbox either; the Xbox button just blinks.
• I've already done the controller firmware update.

The Xbox itself:

• Boots normally and goes straight to the dashboard.
• The Pair button on the console does absolutely nothing.
• USB ports aren't completely dead: my keyboard lights up, but seems to do nothing. It opened an app but that was not repeatable. No way to navigate. I was able to click update console once but not again.
• This started a month ago so I have not been able to use it in a month.
• Tried 4 controllers nothing
• Pressing pair in settings via the xbox app controller nothing happens.
• If I plug power into the Xbox, the controller vibrates twice even without pressing anything.
• At one point, smacking the Xbox caused the controller to flash and briefly behave differently, but it never stayed connected.
• I opened the Xbox and reseated the antenna. After reassembling it and pressing pair, the light flashed twice once, then stopped again.
• I've also tried leaving the Xbox unplugged for a while and power cycling it.

Microsoft wants 800 bucks for a 6 year old console. No way. I got this one for 500 bucks in 2022. 800 is a ripoff for a console like this and the age that it is.

I can't really find anyone else with this same issue. Anyone have any ideas?