Static noise and crackling sound when connecting laptop to external monitor

Question

I have an Acer R271 monitor, Asus K501UX laptop and a PS4 slim. I use UGreen HDMI switch as the monitor only has one HDMI port.

The problem is when switching to the monitor from PS4 there is static noise on the display and sometimes crackling sound, if I switch back to PS4 and immediately back to laptop then the monitor displays the laptop. That is, it takes 2 attempts. Happens every time.

But if I switch off the monitor, switch to laptop and then switch on the monitor then it works fine, i.e., one attempt with additional step of switching off and later switching on the monitor.

Even if I use only the laptop to connect to the monitor directly without the switch, when I connect while the monitor is on there is the same static noise display and crackling sound. I have to remove the HDMI on the laptop end and connect again or switch off the monitor, connect the laptop and switch on.

1. I am worried that my monitor or laptop might get harmed. Is it possible?

2. Is there a solution for this?

3. Finally the UGreen switch says it supports upto 3840 * 2160 @ 30Hz. But my monitor is 60Hz monitor. Will the switch reduce the refresh rate when the output is displayed to the monitor from my laptop or PS4?