So what's causing the incompatability, and what TP-Link router should I use as a replacement?

Also, this problem is the same in NAT mode vs. BRIDGE MODE. If I leave the Rogers device in normal/NAT mode, the exact problem still happens. I just mentioned both being in BRIDGE mode because that's...

I've used a TL-R600VPN with TELUS for over 6 years. Works perfectly, no issue whatsoever. A few years ago, Shaw came around promising 500Mbit/sec, so I tried it out. With a single device (laptop)...