3 4K Displays with M4 Pro Mac Mini

I have a M4 Pro Mac Mini and am having a hard time getting 3 displays to work with it. I'm using USB-C to DP cables for everything, but can only get two displays to work at once - Each combination of two works, so I know cables/monitors are good, but the third one just never comes to life. I manually the two working displays to 4K@60 on the mac, but again didn't seem to help.

I have tried all 3 connected directly to Mini via USB-C/TB->DP cables, I've tried two using TB and one using HDMI, which made no difference.

Am I missing something with how many displays the M4 Pro supports, or am I just doing something wrong here? Monitors are Samsung GS80D, so nothing special.