Lately I’ve noticed that when I boot into Recovery Mode and run DU from there it’s taking a long time to just get my internal SSD mounted. When I click on the SSD volume and hit the Mount button I bet I have to wait for 30-60 sec just to get the dialog to enter my File Vault key. During that wait there is zero GUI response or indication that I have to wait. If the cursor didn’t move I’d think the thing crashed.
Once it comes up, interestingly enough, the preselected entry there for user name is a bunch of hex garbage. If I enter my password with that it won’t authenticate. I have to select my name from the dropdown menu to get it to work. That again lags many seconds. If I move the cursor to hover over the menu bar I get the stupid spinning beachball.
I have no idea what caused this laggy behavior, but I don’t believe this has always been the way my FileVault internal SSD behaved on my MBP. Could this be Mojave upgrade related? I only finally crossed that bridge a few weeks back.