Phoenix 1.7.11 longpoll and apache reverse proxy

with an apache reverse proxy this configuration was ok until the last 1.7.11 with longpoll

ProxyPreserveHost On
ProxyRequests off

ProxyPass /socket/ ws://192.168.190.21/socket/
ProxyPassReverse /socket/ ws://192.168.190.21/socket/

ProxyPass /live/ ws://192.168.190.21/live/
ProxyPassReverse /live/ ws://192.168.190.21/live/

ProxyPass / http://192.168.190.21/
ProxyPassReverse / http://192.168.190.21/

Protocols h2 http/1.1

now I get the error an error 500 for /live/longpoll

the solution was to add

ProxyPass /live/longpoll http://192.168.190.21/live/longpoll
ProxyPassReverse /live/longpoll http://192.168.190.21/live/longpoll

before the lines

ProxyPass /live/ ws://192.168.190.21/live/
ProxyPassReverse /live/ ws://192.168.190.21/live/

susbsidary question:

the connection goes directly to longpoll and not ws, but why since web sockets are enabled on the server ?