Welcome!
It could be a bug, in which case you would report it to support, but from the description it sounds more to me like this is an issue with modes.
The short answer is that nothing in a routine will run if that routine includes a mode change and the system is already in that mode. It just isn’t how Smartthings works.
This most commonly trips people up when they are setting up a routine for when people come home. And then they find that it only works for the first person who comes home. So the explanation is in the following FAQ. I understand this is not your specific issue, but take a look at it because it might explain:
If that is the issue, then the easiest workaround is just have two copies of the routine. One changes the mode, and one doesn’t. You set the one that does change the mode to run based on your automatic conditions. And Then you can still manually run the one that doesn’t change the mode whenever you need it.
If after looking this over you think this is not your issue, just give us some more details and we’ll see if we can help figure it out. 