Drawing tools not responsive after selection tool is used.

First off I want to say this is a great tool, one of the more intuitive ones out there. Glad to support the beta. I'm having an issue where I will be making a tile set and cannot draw anymore. It happens after I use the selection tool. Specifically, I'm taking a part of a different tile, then filling in the rest per the tile, be it a corner tile, side, whatever. Once I've selected, copied, and dragged my chunk of texture into the new space, my drawing tools do not work. The draw tool itself, the fill tool, the draw rectangle tool, nothing actually draws. The rectangle tool does it's thing with the tool tip, to show you the width and height you've stretched from it's origin, but the view-able rectangle is not shown. 

My opacity is max, btw...  it's not a permanent issue. If I switch between the tools a few times or undo a line stroke, it seems to come back. This recent time has been quite a while and hasn't given me back the draw ability however. 

Attached an gif of the struggle