Accordingly to your screenshot the keywords are highlighted in JSDoc comments (/** denotes JSDoc while /* is just plain multiline comment).

The IDE can have special handling to improve readability for certain elements in Doc comments (e.g. code samples etc)... but in this case it has no such highlighting for keywords. So this has to be coming from a 3rd party plugin.

1. Material Theme UI plugin (if you have it installed): please disable that plugin (Settings/Preferences | Plugins), restart the IDE and check again -- does the issue persists?

2. If that helped then we clearly have identified what plugin is causing this. Enable that plugin back and restart the IDE.

3. Now check if you have Language additions option enabled in that plugin settings (Material Theme Settings > Other Tweaks tab). Please disabled that option.

In the standard settings it is not highlighted. I don't know if you changed something but i can't recreate it...

Maybe just remove the second "*" on line 1?

    /*

in, false , true, const
 */