Without TP-LINK is everything ok with stability? Can you check it?

I know it, but I told you about enter those DNS addresses in this tab. For example google DNS (8.8.8.8 and 8.8.4.4) or DNS from your provider it's your choose.

I told about router settings and DHCP Settings tab.

I think that you mean WAN port, yes?

This is what you read, repeater has negative effect for wireless network speed and stability because one radio interface must receive and transmit signal in this same time. It generates delays and...

I think that wired connection will be better for cameras and network streaming. You must to know that repeater mode has negative effect for network speed and stability.