AGREED! They took away that pop up warning that you have it in CAPS LOCK. I miss it as well, but I've learned to check this first thing if the program squawks at me that the password is wrong.
The question is why did they take it away and what is the possibility of bringing it back? I know to check it also when the program squawks, but it still requires a number of extra keystrokes to re-enter with the correct case type.
They rebuilt 2018 from scratch, so many things that worked a certain way in 2017 and prior didnt happen in the 2018 program, and since they were focused on making the program work properly for things tax related, this appears to have been forgotten.