User blog comment:Rappy 4187/Technical Update: June 28, 2017/@comment-1537751-20170630143218/@comment-126761-20170630162036

Indeed - if you're running into this when just trying to chat normally, that's not intended. We introduced some rate limiting to avoid issues of spam causing server problems, not to annoy people :)

We've let the technical team know, and we'll be looking into making the limit more lenient.