I have this same problem, and I'm not satisfied with the answer to just ignore it, because it's not only that, it's causing real problems.
I have a "per user" install (which basically means it's installed on this machine's C:\Users\user.name\AppData folder instead of C:\Program Files), and concurrent licensing, and now when I go into licensing to check out a license so I can disconnect from VPN, the option is grayed out.
The info tip says that
This functionality is not available without the ArcGIS Licensing Service being installed. The service can be installed by running the licensing service installer located within the ArcGIS Pro installation folder.
Well, I don't have any idea what that means. I've looked under the executable folder in my AppData folder, in the folder from which the program installs in the first place, and even on the unpacked DVD ISO, and I don't see any setup.exe for just a licensing service.