I think the point is what you really need in those routers. For example, if you think speed or one feature is very important, then you compare two brands in that perspectives. They have datasheet or...

What's the model number of your router? Try change 5G channel. https://www.tp-link.com/en/faq-2292.html

TP-Link smart bulbs are not dimmerable LED, it can't work with dimmer switch. Various brands of dimmerable bulbs used in mixture are likely to lead to compatibility problems, they may flicker or...

None of tplink smart bulb has that feature.

Not really.

How about firmware? Could it be the router blocking it?