Market Press wont let me delete variants

I added a variant on a test product and now I want to remove it and marketpress will not let me. I select All -> Delete Variants -> Apply

Then a small pop up comes up saying:
Delete 1 product variant


You are about to delete selected variants.
If you want to continue please confirm.
I confirm and it's still there.

There are also two input fields what show at the bottom and then disappear.

Staff Access is still enabled