Had Graywind blinds working with HA over Zigbee for a couple of months. Today they wouldn't interact with HA any more. No matter what I tried I couldn't get it to work, so eventually I deleted it from Z2M. I did NOT enable the option to prevent the device from rejoining. And yet, I can't get Z2M to see it (though when I permit join other new Zigbee devices join successfully) to even interview it. Is there a config file in which this device might have been incorrectly blacklisted?
#Z2M device which was working can't rejoin
gaunt sorrel
sharp haven
Z2M should still allow the device to re-join the network, even if it's completely unsupported.
I'm guessing your device is just not trying to join any Zigbee networks. There's probably a reset button on the blinds. Did you press that for ~6 seconds? It should rejoin afterwards.