@Panda_in_UA Please check if you enabled the Reboot Schedule on the router. Disable it, then confirm. Are you using the original power adapter that came with the router? What is the spec, is it 12V...

@dpkrwt Can I have the detailed network topology/diagram? How do you connect Archer C6 to the network? Any special settings on the C6 itself? What kind of VPN server you are trying to connect to?...

@JFRuest Does glf's suggestion help? https://community.tp-link.com/us/home/forum/topic/255596?replyId=606054

@justWoody If possible, please try with a different phone, you can try it on an Android or an iPhone with a lower iOS version. To locate this issue and try to fix it, we would like to follow up on...

@ColeSlaw71 What is the wireless security on the AX6000? Try changing to WPA2-PSK.AES for both the 2.4G and 5G network, then confirm the connectivity on the iPhone 12 Pro. BTW, does iPhone 12 Pro...

@akg11 Try TomDumo's suggestions to check the QoS settings on the AX11000, or you can follow the guide to disable it: https://www.tp-link.com/support/faq/3069/ If this doesn't help, you can also try...