haproxy webtunnel fail claiming Tor browsers headers are malforned

I was tying to spin up a webtunnel bridge using haproxy instead of nginx, since that's what I use for ssl. It fails because when I try to connect from the Android Tor Browser haproxy says the http headers are malformed. This is beyond what I can pursue and you don't claim to support this but haproxy is pretty well regarded and this might be telling you something. Anyway I was urged to report this and happy to cooperate if you do care to follow up. Thanks