That should work but it's worth noting op that the transaction might get lost again so you'll have to keep repeating that until your next confirmed transaction as otherwise it'll be flagged as a double spend transaction - unless confirming it means your wallet sees it).
without seeing his transaction i can not say anything for sure, but transactions don't just get "lost". there should be a reason for a bitcoin node to drop his transaction out of its mempool.
and also as long as it is an RBF transaction, it won't be "flagged" as a double spend. majority of nodes understand RBF and will replace the old transaction (drop it) with the new one.