Because you've tried different PSU's my guess is that the USB-C PD connection in the miner is messed up and is not reporting the PSU capability correctly.
yes, I believe that is probably the issue, I might try to see if I can desolder the current USBC connector and solder a new one. Nothing to lose I guess.
Good luck getting help. That company is a mess with it's software. They have so many issues and they just made a single firmware which didn't fix anything other that the issue hundreds of users reported. It took me weeks to get a link to download the tools.
Try, force them, but I wouldn't expect much from Canaan.
They are reading here in the forum, there are posts from them, why don't they responding, why don't you get any useful help from Telegram?
NotFuzzyWarm is right when he says they should replace it. Try it, I hope you get a replacement.