If I create a block of text, and then scale it (command-T), I can't input a new leading (line spacing) amount. It does some weird stuff inside the field. In the attached screenshot, I tried to change the leading from 14 pt to 16 pt. This is what happens: changes to .62 pt6. then gives me an error of: Invalid numeric entry.
If the block of copy was not scaled (command-T), then the leading responds correctly to what I input.
This was not an issue in CC 2017.
That was a bug with CC2018 (v19.0) It was fixed in the 19.0.1 release earlier this week.
19.0.1 does introduce a new issue in that the enter key needs to be pressed after adjusting values - but at least the leading values can be entered consistently