"undefined" no longer highlighted in Webstorm 2020.2

Hi, 

I updated to Webstorm 2020.2 today, and I'm enjoying the new features. However, there is one major annoyance: the keyword "undefined" is no longer highlighted. It seems to be indexing it from Node somehow, because if I go to implementation, it takes me into a file deeply buried into the node_modules folder.

I tried wiping the cache and reindexing, but to no avail. I don't want to exclude the node_modules folder, because I don't want to lose functionality, but it is pretty annoying, and it happened only when I updated, so no configuration (on my end at least) changed.

Any ideas? Anyone else facing this issue? 

Thanks!