According to Coincashew, to cancel a deregistration of the pool you have to resubmit a new certificate. I did it, and also tried with the old, but nothing happens. It is received but the pool [CURE] still says it will be retired in epoch 275.
Do I have to repay the deposit fee? I am removing that parameter from the cli command when building the transaction so it does not subtract the deposit fee again. Any clues on how to do it properly?