I have exactly the same problem, with the same router AC750. First the problem was intermittent for about 4 days, then BOTH Facetime AND iMessage (iOS)-Messages (Mac) stopped operation through the router. The apps work fine when I connect the computer to the ISP modem directly.

Firmware: 0.9.1 5.0 v0032.2 Build 170228 Rel.38431n
Hardware: Archer C2 v1 00000001

Have updated firmware, reset to factory settings, and also toggled the Router's Firewall on-off without any resolution to the Facetime/iMessage/Messages failure to send-receive.

Other behaviors seem totally normal.

Thank you.

Hi,

Email I received from TP link.Dear customer, good afternoon. Thank you for contacting us and for purchasing our products. Please, sir, do the procedure below.Access the TP-LINK interface through a computer connected via cable to the router by typing 192.168.0.1 or 192.168.1.1 in the browser's address bar;Put in the username and password "admin", and log in;On the left, click lan / wan or network interfaces.On the left side, click wan.If the connection type is Dynamic IP in the center of the screen, change the MTU number to 1305 and click Save or Save on the bottom of the screen.If it is PPPoE go to the end of the screen and click advanced or advanced and at the beginning of the screen that opens change the MTU to 1305 and at the end of the screen click save or save.On the left, click on wireless.On the left side, click advanced wireless or advanced wireless.In the center of the screen, disable wmm.Click save or save.On the left side click on DHCP and the last 2 lines include the following primary DNS: 8.8.8.8, Secondary: 8.8.4.4.Click Save, and then Restart.

Good morning.

I just tried this solution and it has resolved the issue. Thank you very much to whomever had the idea at TP-Link.

I still do not understand why the router worked normally for almost one year without setting the DNS IP number explicitly.

Best regards.