It could have been, as you suggested, that you had one of the devices powered down for awhile at the breaker. If those 3 blinds were routing back to the hub through the unpowered device, they would have been stranded and might have been searching for another route home. If your mesh wasn’t yet strong, such that the blinds only had that one route home, they would have become discouraged.
Just throwing that out as a possibility. Without a packet sniffer on your network, it’s hard to know.
