Anyone have this problem that the second monitor display quality dropped but the it's totally fine working as the main monitor? I cannot find any proper solution anywhere around the net but avoiding like changing DPI which doesn't solve the issue. Anyone knows the way around it?

GPU RTX 2060
1st monitor connected with HDMI
2nd monitor connected with HDMI with display port adapter to GPU
both are 1080p 1920x1080(recommended)
Windows 10 pro 1909