This is a problem I’ve been getting. I don’t have any other second monitor or something.
Here is a link to the video I’ve recorded.
After that if I wait for long it reboots.
Im using lenovo v15 g4 amn.
There is a delay in the input, so it is not smooth. So how do I fix that?
Hi @Spidychoi
Welcome to the forum. 
Just to rule out overheating.
- Are the fans clean of dust?
- Does the laptop get hot?
Welcome to the forum

Another thing that comes to mind is if there is a USB stick present that might be causing the delay.
Is the iso verfied ? tried with another usb ?
Edit: Only dutch users are replying 