Thanks to MacRumors for this thread.
I have the iPad Pro 9.7 and the keyboard had been a little quirky from the start with the “h” not always working (I thought it was me not hitting the key hard enough). Then the last few months I would get the Not supported message intermittently. Sometimes I would just reconnect and it was fine. Other times I’d have to reboot the iPad. The last two weeks it’s been working fine. Also the sides of the keyboard came apart which was just yucky.
Because of this thread, I went to Apple today and received a new replacement keyboard. Easy, peasy - didn’t even have to get tough or plead my case. They took the serial number of the old keyboard and gave me a new one. So far working good.
Thanks again, MacRumors!