Known issue with PATCH requests?

I keep PhpStorm updated with Toolbox and it's been like 3 or 4 days now that some *.http requests get stuck running forever. It tends to happen with PATCH requests. Some times the request completely finishes (I can see that in my application logs), some times it doesn't even start. If I export to Curl, it runs almost instantly. Not all requests are affected, but when one is, it stucks every time.

It might have to do with builtin functions, because this request doesn't start but it does when I use a static value:

PATCH http://redacted:5000/api/v1/holidays/19
Authorization: Bearer {{token}}
Content-Type: application/json

{
    "date": "{{$random.integer(1000, 1999)}}-12-15"
}