TextExpander often doesn't become active, although it appears to be active

It often happens that TextExpander (“TE”) does not respond to my snippets. I have the program seemingly open, but it just doesn’t work. It comes and goes, and I don’t know why. For instance, right now I cannot see TE even though it is supposedly active.

I use TE both in MacOS and Windows. Right now, I am on my iMac. I also have a Mac mini at another location, and I have 2 Macbooks.

In Mac, I have TE visible in my dock, and the dot that shows it is active is visible. Nevertheless, I cannot open TE by clicking on it. Just now, I tried a snippet, and it works! So, the problem is intermittent. I am a long-time under-utilizer (I made that word up), but I want to expand my use of the program.