u do 4k streaming?
or do streaming yourself?
or always download very big files >10gb per file?
or a lot of people in your house sharing the internet?

generally speaking, 100 mbps is suffice if none of the above applied to you.

What sources are you downloading from? Can the source allow you to download @ more than 30mb/s? If so, then 300mbps is good.
Me download from steam 10 gb only a few mins.. It's been satisfying experience. I can uninstall a lot of my games and only install when I want to play it.

any idea why suddenly unifi lite dload speed capped to 1.5Mbps? mine is 8Mbps plan but since afternoon the speed is capped below 2Mbps.

100 Mbps ?

if your device infront of your router, yes
if your device far from your router, you might see 5Ghz perform worse than 2.4Ghz
higher frequency get better speed but difficult to penetrate wall etc... and coverage is smaller, unable to travel far
lower frequency get better coverage with better penetration, because travel far, in exchange speed is lower

uplay also cannot but battle.net can. uplay suddenly can but very slow

Try with VPN...Dont hope TM fix this big shit problem in short time...

express vpn or nord vpn