P2424HEB, doesn't detect signal from laptop(s)

Hello,

I have two laptops connected to the same Dell P2424HEB. Everything is up-to-date. Those are connected as follows:

• Laptop 1: HDMI for video, DP<->USB-B for audio
• Laptop 2 (Dell brand): USB-C for everything

There is a second Dell monitor connected to the P2424HEB with a DP cable but let's leave that aside.

The problem:

• Assume both laptops are on. If I shut-down Laptop 2, the monitor doesn't switch to Laptop 1.
• Assume all laptops are off. I start Laptop 1, the monitor is still asleep.
• Assume both laptops are on. Sometimes even after switching feed using KVM of Dell Display Manager 2, the monitor says "no signal".

Because of all the issues above, I use the button behind the monitor to change feeds often. Not only it is an out-dated thing to do but one day that button will wear.

Do you have any suggestions?

Thanks