Latest Eclipse plugins, for version 11, have no syntax highlighting and no code completion ("code assist")

As the title says: I use the eclipse plugins that ship with CUDA 11. I have downloaded the latest Eclipse, but I get no syntax highlighting and no code completion. Building/compiling works, and it throws errors when I make some dummy mistakes, so the build process seems to be fine. But no code assist / code completion, and no syntax highlighting at all. I tested it by configuring all matching braces in green and bold, the editor doesn’t do that. Nothing, just the black on white text. Very frustrating.

Update: I got it to work when using a new, fresh, separate Eclipse installation – one that is “pure” and doesn’t have the Scala plugins. It seems best to have one Eclipse for Java, one for Scala, and one for C/CUDA. They can all still use the same workspace, although using separate workspaces then is the next logical step. Still don’t have yellow background for device code, but at least I have (most of) syntax highlighting and command completion / code assist back.