Hi @JamesT,
This new behaviour is a side effect of the Menu overhaul we released in Supernotes 2.1.0. We started to make the menus more accessible so you would be able to tab through them, but this behaviour is not fully-completed yet.
We will look into reverting the original behaviour so tabbing from the card title will take you straight into the card content. In the meantime, pressing the down arrow key ↓ will take you straight into the card content from the card title (and vice versa using ↑ if your cursor is at the start of the card content).