I just tried doing that with alby today, before they shut down their custodial wallet.  I was able to move all but 15 sats off of it.  I think each wallet has their own rules for that, but when i tried moving the last few sats it said the amt did not meet minimum amt, so i gave up. Never messed with wos much though.  You might try moving smaller amts at a time.  Today with alby i tried moving the balance all at once, but didnt work (a few thousand sats).  Then i tried moving smaller amts, which worked till it got down to 15 sats.  Thats all i know about it.