Haven't seen any mention of this anywhere, and it's bin bugging me all morning. ;)
My system is 10.0.5 with MC 8.6.3. New user when I installed 8.6.3, and I also tried with a new user with stock settings. Bins are in regular "Text" mode.
- highlight a sequence in a bin,
- hit CMD-D to duplicate it, a copy is created and its name is selected and can be changed right away,
- change the name of the sequence,
- hit Enter (on the num-keypad, or via FN-Return on wireless keyboard) to get out of typing mode, so far so good.
- hit Enter a second time (or Return) to load the new sequence in the Timeline/Composer: nothing happens.
From that point on, the keyboard doesn't do anything in the Bin: the up/down arrows won't let you move to another clip, and Enter/Return won't do anything. I have to either manually double-click on the sequence to load it. Hitting Return to load only works if I mouse around selecting other stuff in that same bin, or clicking on different windows before coming back to the one I really want. It's marginally annoying, especially when you're used to the efficient ways of moving in a bin only with the keyboard.
Can reproduce this?