The dry run return quickly with no error message? That means ZFS would be able to import. The “quick” part is puzzling, as we’d expect to wait quite some time while ZFS rewinds and checks at which point it can import.
In an other thread, @HoneyBadger asked for
the contents of
/proc/spl/kstat/zfs/dbgmsgimmediately following thezpool importcommand.
and it may be worth checking here as well.
Pending that, if you accept the risk of losing some recent transactions, the next step would be
sudo zpool import -R /mnt -fFX pool
Always add -R /mnt to any real import to mount the pool in the right place.