Allow the action. What makes zero sense is the combine option(s) appearance is that it is available, however, it is only a mock appearance. That should be removed, it misleads a user (novice) to thinking it can be used but it only looks like you can click on the final option to combine. It will only hurt your feelings because after it's all said and done; you're not combining anything and everything you just did was a total waste of the time. To me that's not worth learning how this application works. Wasting my time is (to me) is theft.
Allow the action or remove the option, at least on the mobile app. I was ****** to find out my time was wasted trying to do something within this app and it was never going to work, so gee thanks for using your time wisely by reading my idea. Hopefully, it will be considered and agreed with by the whole Google community.