When using an intranet IP address as DNS, you may not be able to access the DNS server

Hello i'm using this AX 3000 wifi 6 router with tailscale,
having this error if you can find the attached, but i have 0 information about networking and stuff,
i tried to add public DNS like (overwrite local DNS on/off) but nothing works.

could you please help me....

Can try manual change custom DNS server in the GL GUI -> Network -> DNS

Is the Internet access of devices unavailable when you enabled the exit node of tailscale? Please confirm if the GL router has been approved the subnet in the tailscale cental

So I did exactly what you did in GL GUI -> Network -> DNS, then chose Manual DNS and then chose an option (Cloudflare public DNS, that automatically filled the DNS Server 1 and 2 as same values in your screenshot). and the DNS error not visible anymore as you see in my screenshot (but also the DNS is not visible as well)

  1. If I connect to the router from home on my laptop (doesn't matter if it is as exit mode or not) I don't have internet on the same laptop, Also I connect on the router through my phone, also there is no internet (keep in my mind that im still in my home, and didn't try that outside yet, but even though at least the main laptop should have internet if connected to the router, or am I understanding it wrong? cause as I said before I really don't understand all these Network stuff

2)I don't understand your question, Please confirm if the GL router has been approved the subnet in the tailscale cental? how to check on that?

  1. if you see my screenshot, there is also that warning on top, also i don't know how to make sure that on tailscalse is working or not?

in this screen shot also i see:
This machine has unapproved routes. Review this from the “Edit route settings...” option in the machine’s menu.
maybe this is what you mean in your question
unapproved

And i fixed that as the sentence say, clicked on Edit Route setting and then approve all routes, i can now connect through my phone

But still when I connect to the router through the main laptop, it does not have internet if connected to the router (Exit node), is that correct, or should still have internet?
bear in mind, that the router is connected to the home wifi, and the laptop is connected to the router, but no internet, while if i use my phone and connect it to the router, it works on my phone if only the laptop run as exit node, but if not exit node, there is no internet on my phone too.

last step: but need to go out for a coffee shop or something to test and see if the public IP address is my home address.

Laptop be supposed to have Internet access via router even if the router connected to home WiFi in home.
But you can go out like shop, hotel, etc. others Internet source, to test if it works.

If not, please share us your topology figure including the laptop, GL router, tailscale exit node devices, etc.

yep I will try that maybe this weekend, but yes in home there is no internet on my main laptop which is the exit node when connected to the router, where the router is connected to home wifi.

so I tried that outside my home, and it works when I connect through my phone and through my friend laptop, but not my work laptop, the problem that i'm not able to connect to the router from the work laptop.

i have same problem from my home when i try to connect the exit node laptop to the router, it does not accept it.

so i don't know what could be the problem