Your experience very similar to me

Monacoin always makes a headaches when it became to transfer.

I've Mining Rig GTX 1070 too

tried suprnova for some hours
I've made about 0.70 Mona Coin about 11$

Tried to withdraw it.
it's done successful. then I've made a transfer to another wallet.

Unfortunately the fee was 0.0001 MONA

and its stuck for 4 days now and I think maybe forever?!!

that's it.

I've moved to miningpoolhub
Currently mining multi coins for bitcoin with auto exchange as a Nicehash alternative.

no more headaches :)