All 9V batts have little CURRENT capacity (not many milliamps) -- even alkaline ones are not that great. Just think what physical volume even 6 pcs of AAA 1.5V batts is, compared to that small brick-like 9V batt. Current output CAPACITY, declines some - along w/ falling voltage, as the batt continues discharging. As for 5V USB chargers: almost all the more-recent ones - at least if they're "higher power" - use a COMPLICATED handshaking routine with the device they're connected to. They will output different, higher voltage (than the standard +5V), IF they get a certain response from the device being powered. That may well "confuse" the Coldcard (which may not even participate in that optional handshaking procedure). Just my GUESS, I'm not sure if that's a/ the cause of USB powering troubles. Either way, if the non-firmare-updated Coldcard is all you've got, better FIRST just move all your stack(S!) somewhere else - even (UGHHH!) to an established exchange, just long enough to TRY to update your CC - or get a new HW wallet. OR, maybe better: send to a NEW Sparrow, Specter, Aqua, etc software wallet - but be CAREFUL not to let its seed be exposed, since any software wallet is often connected to the internet. My deepest condolences to those who've been robbed already. I am not free of the guilt of having spoken of Coldcard as about the most-respected hardware wallet - without having MYSELF verified their safety! I'm not even qualified to make that assessment by myself, but I own several of them (w/ smaller stack amounts) .