In 3086 any tool can stop working when selected using keyboard shortcuts. This is similar to the bug Glyphs has always had with the select tool becoming unresponsive until the text tool has been used but worse. Sometimes when a tool is selected it cannot be used and neither can any other tool. To fix the problem glyphs has to be restarted.
I have never seen that behavior. Does it happen for anybody else?
Can you start Glyphs with Option+Shift key pressed to disable plugins and check if it still behaves like this?