ReSharper 2017.2 is extremely slow when editing Typescript

Something eats one of my CPUs and VS keeps going unresponsive (devenv.exe turns red in perfmon). Keystrokes get dropped, when I try to just type ahead. (Not to mention that VS becomes basically unusable.)

This only happens when editing a TypeScript file, and doesn't happen when I suspend R#.

I've tried a couple of the performance tuning tips on the "Making R# go faster" page, to no avail.

This is in a .NET project using Razor MVC (the solution is a piece of your standard bloated "enterprise" app created 20+ years ago). VS 2017, TypeScript 2.5.

I have node/npm installed on my system, but this VS solution doesn't use it. There is no node_modules subdirectory or @types or any of that claptrap. I do have a "typings" subdirectory with jquery and bootstrap typings files specific to the versions of those libraries we're using (and no others; more specifically, we didn't just download .d.ts files for every version of jQuery and bootstrap). We're also using a third-party Bootstrap theme that comes with its own Javascript silliness and some plugins, but it's not too bad.

I don't see any issues posted on this, so I must be missing something. What's the fix?