When trying to import using "import transaction (raw)" I get "Push operation exceeds data size".
This sounds like your transaction is too large for mSIGMA to handle for some reason. Are you trying to consolidate a lot of inputs at once? Perhaps split your transaction in to two and try again with fewer inputs?
Unfortunatelly not. I tried first with the 3 inputs I have and then just a solo input. Both didn't work.
I noticed there might be trouble stemming from using a bech32 address as the receiver address and tried with a 1xxx legacy one instead, same results - mSIGNA shows an error upon import.