On Bisq neither the seller nor the buyer has to change anything in the transaction.
This transaction does NOT support Replace-By-Fee (RBF) and cannot be fee bumped using this method
Okay but your transaction was forgotten by the network (well maybe not my node, but my 2GB mempool won't be relevant until the mempool of other nodes goes down in memory usage).
What you want to look at, is fullrbf. FullRBF happens even when a transaction does not support RBF
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