40Gbps is utilized for the USB4 move-by way of port, when the 2nd Thunderbolt port distributes 40Gbps of bandwidth to the remainder of the ports on the hub. Look at if there are dust particles or dirt in the USB-C port. If any, clean using a can with compressed air. https://hdmitousbc54308.ziblogs.com/26771997/adapter-for-macbook-to-hdmi-secrets