External monitor connecting to MacBook Pro and turning on for half a second, only to black screen while still maintaining connection.

I've recently acquired a new monitor, and I'm having a hard time connecting a specific MacBook Pro (13-inch, 2017) to it. This monitor (Dell S2721HGF, if curious) has an HDMI port, and I'm using an HDMI to USB-C converter to connect the two. My issue is that, while the MacBook Pro can successfully recognize and connect to the monitor, the MacBook only projects to the monitor for about half a second or so; after which the monitor turns black while the MacBook Pro believes it continues to project to the monitor. I can visually see the monitor functioning as it should for half a second, then nothing. Furthermore, I know this issue is specific to this exact MacBook Pro and this monitor. My MacBook Pro has successfully connected to every other monitor I have, and even another MacBook Pro (2019, 13 inch) can easily connect to the monitor when I take the exact same steps and use the same cords to connect without issue.

This MacBook Pro has seen a lot of its settings fiddled with over the years; if I had to take a guess, I believe that there's some internal setting on my MacBook that's preventing me from sustaining a connection for security reasons or something. I've tried resetting the VRAM already and have searched through my settings and applications looking for anything malicious, but to no avail. Any ideas of what could be up?