@angryfish
Maybe….
….Unless they all got the same software update to the opsys or similar problem.
This has nothing to do with the Qu or your being new to it.
What you describe is a mac/software problem as I see what you have described and not a Qu problem.
You never said you did anything to fix the potential problems on the mac/software.
Until you do that I will still look to the mac/software as the problem not the Qu.
Now if you completely scrubbed the mac, deleted all security software, deleted all social media crapware, fixed the buffer sizes and did the entire list of things recommended to make your pc usable for audio then I might change my mind and look for the problem on the Qu.
Could the Qu suddenly have developed a problem. do’H! its hardware and that is certainly possible.
Like the bookie said: the battle is not always to the strong, the race not always to the swift,
but that is the way to bet.
I am still betting on the mac not the Qu as being the cause of your problems.