Sorry to hear this is disturbing your workflow. The best way to ameliorate the issue at the moment is to add an extra blank line at the end of a card. That way as you add items and tab them, you will not encounter the bug, as you will not be on the last line.
We try to do as much testing as is reasonable, unfortunately sometimes bugs slip through the cracks. The editor especially is a complex system and has a lot of moving parts, so it is difficult to test in a comprehensive manner. The Supernotes 3.1 release was especially sprawling which made this doubly difficult. As we noted around the time of that release, we intend to keep releases much smaller from here on, which should also help reduce the likelihood of bugs like this slipping through.