S2721DGF, MacBook, C925E Logitech Webcam not working

Hi there,

Switched monitors from Dell S2421H to S2721DGF this past weekend. 

On the S2421H, I had the C925E Logitech Webcam plugged into the monitors USB-A port, then connected to my Macbook via USB-C and it worked perfectly.

For the new S2721DGF, I have the Webcam plugged into the USB-A port on the back of my S2721DGF, and then to my MacBook via a HDMI hub.

Unfortunately, the Webcam doesn't seem to connect to my MacBook via this method. I get a green flashing light on the Webcam, and it's not detected by the MacBook. Is this method of connecting the Webcam not compatible / providing enough power for the device?

Thanks for your help!