HeXHub

You're confusing UserIP version 1 and 2. The hub sends the correct command.
When sending the UserIP command for 1 users it would looke like:
$UserIP <nickname> <ip>|
If UserIP2 is supported and multiple ips are sent it would look like (otherwise the same as above):
$UserIP <nickname> <ip>$$<nickname2> ip2>$$<nickname3> <ip3>|

So HeXHub sends the corrent UserIP command.