Try disable your IPv6?
TM IPv6 routing is very bad only can get good routing from Facebook/Google sometimes...
Most of the time 95% of TM ipv6 connection will get shit routing and latency than ipv4.

For Windows
https://medium.com/@JockDaRock/disabling-ip...10-5fad010bca75

For Router
U need to login to the admin management panel of the router and try to find the setting for ipv6.
It should be an On or Off button to choose and save it.

Recent would be ax or WiFi 6, but you will need a device that can support it. No point having an AX router, if you don’t have the right devices to utilize it. What is your budget and your current Internet speed?
If you have a normal 2 storey house, and you really want 500Mbps throughout, you will need several wired AP, and not mesh WiFi. Deco M4 also only supports up to 300Mbps, so not sure what the guy is talking about. You will need at least the TP-Link C9 or A9. I would recommend the C2300, but you might not have the budget for it.

Using STB WiFi is not possible. Best is still wired connection.
Do it from the router. It all depends on what router you have. Log into the router, and find the IPv6 settings and disable it.