Hi,
i could reproduce it and it works as expected. For the sake of logging i replaced validate with my own validate block and the issue persist. the validate server log output:

{"connection":"upgrade","host":"localhost","x-original-uri":"/validate","user-agent":"curl/7.68.0","accept":"*/*"}

The thing i could figure out is if the validate server is in the same host its works, but if it is o a another host it don't.


Thanks.