I found that some virtual instruments, especially the high memory loaded ones, cause Input Latency increase.
This is the state after a fresh start.
This is the state after a vsl vi loaded.
The high input latency issue does not disappear after restarting cubase.
And simply restarting the OS cannot solve the issue either.
The ways I found to solve the issue are 1. wait for about half an hour, 2. restart the OS and enter BIOS setting once, 3. power off all devices and restart again.
Are there any settings I have done wrong ?