The fix to wait until seems to have made things worse.
If you click the Wait Until button it's impossible to enter a trigger because the drop down box disappears before you can click anything in it, and the rule adds a Wait Until null step.
There is no way to actually enter what it is you want to wait until.
Android device, Firefox default browser (proper Firefox not the new unusable Firefox).
Happens from browser directly as well as when invoked through mobile app.
Edit:
Just checked with Chrome. Also does the same thing.