I came across a similar issue using a different USB C hub. Your issue is that your HP hub supports a single video port either HDMI or DP but, not both. Hence, the mirroring.
I purchased a dual monitor support USB C hub from UGREEN.
https://www.ugreen.com/collections/d...ocking-station
This hub features 2-4K video ports. Each port has a DP and HDMI connector. However, to make DisplayLink work properly, on video 1 you would select DP and on video 2, you would select HDMI or vice versa. But, it will not work as DP and DP or HDMI and HDMI. So, you'll have to have the correct cables to support your dual monitors. I hope this helps.