No Signal with Capture Card

I’m having trouble getting my Elgato HD60s + to operate correctly with the monitor. I have an Asus monitor that works perfectly with it but when I plug the output hdmi cable into the spectrum monitor, it says no signal. But if I run a HDMI straight to the PS5, it’s fine. I realize my wording my be a bit confusing and I apologize. Definitely willing to answer as many follow up questions as necessary.

Are you using the „compatibility mode“ on the spectrum?
This sounds like the monitor is configured to use HDMI2.1 but your capture card only supports HDMI2.0