Hi, according to HP: Drive an external display with HDMI support up to 4K or VGA support up to 1080p. Connect to your Gigabit Ethernet through the RJ-45 port and your accessories through a USB-C™[2] or USB port.
No mention if it os 60Hz unfortunately.
If the HP Spectre X360 has a USB-C port that can also do video and LAN, then it works. It's a bit strange that the product says USB-A, because HP itself says that this item has a USB-C port.
https://www.hp.com/ch-de/shop/product.aspx?id=1PM64AA&opt=AC3&sel=ACC
Here is the response from our department responsible:
Unfortunately, we could not find the correct information. The supplier has been in contact with HP support and has not received an update.
The customer can contact HP support directly: https://support.hp.com/ch-de/document/c06296830
A list of devices officially declared compatible by HP is available at https://store.hp.com/SwitzerlandStore/Merch/Product.aspx?id=1PM64AA&opt=AC3&sel=ACC&lang=de-CH#compatibles. The type designation and product ID on the back of the notebook are decisive.
If I have understood the operating instructions correctly, a maximum of 1 external monitor can be used:
http://h10032.www1.hp.com/ctg/Manual/c05927109.pdf