If your ISP is using PPPOE as WAN connection type, you can just reset the D7 to factory default/ delete the PPPOE connection on D7, then connect the router to any port, and do the PPPOE connection on...

How do you find this out? Is it like you can still open Https website when the bandwidth is used out for 1 device? If you don't use IPv6, would it work well? And does this happen for all devices? Are...

Sounds like hardware issue. You may try a different power outlet, power adapter. Try reset the router. Or just contact tp-link tech support to let them check it out.

I think you can send an email to tplink tech support ( suporte.br@tp-link.com) to let them check it out.

Not really good at VPN. But as I know, there is some trouble on MR200 V1 with VPN passthrough, you can try to contact TP-Link tech support to get the beta firmware which fix the VPN Passthrough...

It is weird. You may check on the Everest official website, or contact their tech support to get the new firmware.