Steam remote play together no streaming screen from mac host

I am trying to use Steam’s remote play together to play Death Squared with a friend remotely. However, when they accept the invite, it shows the "live broadcast" screen and nothing else. It does play the audio from the game, but just doesn’t show the screen or give them control.

My host is a macbook with the following specs

MacBook Pro (13-inch, 2017, Four Thunderbolt 3 Ports)

Processor 3.1 GHz Intel Core i5

Memory 16 GB 2133 MHz LPDDR3

I have tried connecting to another macbook over the internet as well as a windows machine on my local network, both exhibit the same issue.

However, I can use the Steam android app to stream the game to my phone without issue.

Also, when I launched remote play together for the first time, a window popped up saying I needed to install additional drivers. I clicked ok, but then nothing happened, it just closed. I tried uninstalling Steam and reinstalling it, but it didn’t prompt me for this installation again.

Why is my screen not streaming?