Assigning lens profile

Tryin g to assign a Tamron lens profile to images in the latest (as of today) Lightroom Desktop on Mac, OS 26.6.

When I select Tamron, the program jumps back to none. I then have to  do it again for it to work. This is happening 100% of the time on two different MacBooks. 

To be clear, it works after two attempts each time, so it's not a setting issue.