I think it depends on the RAM capability of the router, you know, the Traffic Statistics consume memory. The larger RAM is, the more Traffic Statistics can record. But I don't know the exact data....

Maybe you got a defected one? I have a Archer C8, but no issue with VPN and wifi.

It seems that V3 will support cloud service, don't know V2/V1

Never found such an issue. I think you could try to clear the cache of the web browser and then try again.

I have found some information about GP, an awesome production! Which connection type of your router? PPPoE or Dynamic? If PPPoE, I suggest to clone the MAC address of your modem to try. If dynamic, I...

I think you could try to use Wireshark to analyze