U2419H, Surface Dock, mini-DisplayPort to HDMI not working?

My apologies if there is a recent post, but I only saw posts on this issue from 5 years ago. I just purchased two Dell U2419H monitors to use in our office with a Surface Pro 7 and Surface Dock. The connection set up I have is:

Surface Pro 7 -> Surface Dock (newest model) -> mini-DP (out) -> HDMI (in) -> U2419H

In this configuration, the monitor displays "No HDMI connection"

I also tried the two configurations with my 2015 MBP running 10.15.4

a.) 2015 MBP 13" -> mini-DP (out) -> HDMI (in) -> U2419H Result: "No HDMI connection"

b.) 2015 MBP 13" -> HDMI (out) -> HDMI (in) -> U2419H Result: monitor works

Is there a solution for this problem? The Surface Docks only run mini-DP out and I wanted to deploy additional Dell monitors in our office. I have two U2520D's on their way. I have not had this issue with any of the Samsung monitors we deployed formerly. 

Thanks for any assistance solving this.