16" m1 Pro with three external monitors and USB-C Pro dock?

[m0nkeyb0y]

Up until last week, I was running a 16" 2019 MBP with three monitors. One monitor (4k) connected on the left, USB-C>DisplayPort. The other two— 4k and 1080— connected with DisplayPort cables on a CalDigit USB-C Pro dock. I've had no problems running three monitors like this... except always-running fans, which is one reason I upgraded.

I bought a 16" M1 Pro, and plugged everything in the same way, and only two monitors will run at once. It doesn't matter which two. If I have them all plugged in and unplug one, the third turns on. If it plug it back in, no change. Unplug a different one, the replugged one turns back on.
I've tried different arrangements:
A) Monitor #1- USBC>DisplayPort on left Thunderbolt, #2 on HDMI direct, and #3 on DisplayPort from the dock. Only two function. "No signal received."
B) Monitor #1- HDMI direct, #2 and 3, DisplayPort from the dock. Only two function, "no signal received"

Any help or suggestions? I've googled a bit, and just do not understand this.

 

[seadragon]

I don’t have multiple monitors so can’t help directly. But here’s an article from Apple if it might help. There is a difference between Pro and Max. Pro supports only 2 external monitors according to this.

MacBook Pro (16-inch, 2021) - Technical Specifications - Apple Support (CA)

support.apple.com

Display Support​

Simultaneously supports full native resolution on the built-in display at 1 billion colors and:

• Up to two external displays with up to 6K resolution at 60Hz at over a billion colors (M1 Pro) or
• Up to three external displays with up to 6K resolution and one external display with up to 4K resolution at 60Hz at over a billion colors (M1 Max)

 

[m0nkeyb0y]

I don’t have multiple monitors so can’t help directly. But here’s an article from Apple if it might help. There is a difference between Pro and Max. Pro supports only 2 external monitors according to this.

MacBook Pro (16-inch, 2021) - Technical Specifications - Apple Support (CA)

support.apple.com

Display Support​

Simultaneously supports full native resolution on the built-in display at 1 billion colors and:

• Up to two external displays with up to 6K resolution at 60Hz at over a billion colors (M1 Pro) or
• Up to three external displays with up to 6K resolution and one external display with up to 4K resolution at 60Hz at over a billion colors (M1 Max)

Only two directly. But apparently you can make it work with a Thunderbolt dock, which I have.

 

[m0nkeyb0y]

I've tried installing the DisplayLink manager and rebooting, no change.
Also, I'm running in clamshell. Turns out I can run two external plus the laptop display simultaneously, but that doesn't help me.