Random 502 errors for last 3 days (caused by illegal request header injected by CF reverse proxy)

I came across this topic in search of an solution for the 502 error we randomly get. Currently it is 1.5% of our traffic.

We run multiple Azure Web apps but it seems to happen only with the one we still have on .NET 4.7 (All other projects are on .net core).

In our application insights I cannot find any errors related to the 502.

So while there is an comment that it is resolved. I think it is back for the last 2 days (for us then). Also created an support ticket for it #1986626. Hope that Cloudflare now response faster then 4 days as our customers are complaining about this issues.

akrivit, can you confirm you guys are still testing on prod with changes that can relate to this 502 issue?