Just to make sure that it’s clear: ckBTC is still under development, so there is no guarantee that things work end-to-end.
I don’t know what’s causing the behavior you’re seeing.
Of course, you are free to experiment with the existing code but it might be easier to wait until the ckBTC launch, at which point the code will definitely be stable and well-tested.
You are trying to retrieve “retrieve_btc_min_amount=2” which is 2 Satoshis. This can be the source of your problem. Because if the amount you are trying to retrieve is lower than the fee you have to pay it won’t send the tx to the BTC network.
Which arguments did you use to initialise the minter canister ?
One reason for such behavior could be a failure to obtain an ECDSA signature or submit a Bitcoin transaction. The insufficient cycle balance of the minter can cause such a failure, for example. How many cycles does your minter have?