I have noticed lately on the new OS X updates that when you copy and paste - there are some characters that throw off compilers or linters.
Retyping everything exactly how it appears solves the problem. I believe there may some hidden characters or something causing this with Apple’s latest updates.
Copying from web pages commonly causes this problem because of the way the web pages are rendered. This also may be true copying from word processing programs, or pretty much anything that isn’t strictly plain text. Catalina may be doing something new and different but the issue isn’t specific to it.
Usually unusual space characters are the problem, like non-breaking spaces and em spaces.
There’s a package available through Package Control called “Highlight Dodgy Chars” that I believe flags odd ASCII characters in code. This might help you, but I’ve limited experience with the package.