When trying to install Final Cut Pro via Self Service today, I was not having success. I was not getting anything in the logs or device record either. Nothing. Then I remembered I had initiated some updates in Creative Cloud app...Premiere, etc.
I had attempted to install Final Cut again, no go. Waited for Creative Cloud to complete, then installed Final Cut Pro via Self Service successfully.
The current Adobe installers are very finicky about what is running while they install; for instance, if you have Photoshop 2020 running, and try to install Photoshop 2021 via a policy (self service or not), it will fail and not give much of an error message. My guess is an active install via the Creative Cloud app has the same effect.
Since it's not really feasible to kill all open Adobe applications before doing an install, we've been handing it by notifying users before the policy starts it's run.