@Namann1 

No, the QuickSetup set automatically IPv4/IPv6:

I did a research and I fear in Iitaly the IPv6 protocol on mobile networks is not supported yet. If I check my ISP website https://gizblog.it/2018/05/apn-iliad-come-configurare-parametri-sim it tells to set the Protocollo APN: IPv4.

I try to create a profile with just IPv4:

I give feedback in a few minutes.

@Namann1 

If I run the test I always get No IPv6 address detected (see previous post) no matter if I set IPv4 or IPv6.

These are the tests with IPv4/IPv6:

If I set just IPv4, I get a timeout on different IPv6 tests randomly:

Using just the IPv4 the Basic tab says connected:

@Emaborsa you should set PDP type to ipv4 as screenshot and then try to access website..there is unavailablity of ipv6 in your region, so set ipv4 only...there should be no problem but..if you tried to reach ipv6 only website than that should be not loading...if any ipv6 site no loading or any error pops, just try to contact ISP, there is no problem from the router side...thanks

@Emaborsa one more thing, try to turn off ipv4 and ipv6 firewall and also turn off content restriction from parental control..

@Emaborsa you should set authentication type to none according to your ISP..

@Emaborsa 

The initial problem seemed to be solved, but each few days the router was freezed, 192.168.1.1 was not available at all, required to unplug the power and restart it.

Item returned to seller, will never buy TP-Link stuff again, sorry.