I try setting my router but internet still no connection

Hi, ive recently bought a SG605 switch from TP Link. is it normal that speed is reduced from 920mbps to 770 more or less and that internet suffer some small variations? With ethernet directly connecte

If I try the online upgrade method, I get download failed. If I try to download the firmware and upgrade, I am getting Error 4503 if I try to upgrade firmware. I'm downloading the firmware from this l

Can the above router be used a part of a mesh wifi network? is there a software update for the router to be be able to do that? What extenders from TP link can be used in such a network?

My TP link router is archer c60 model and this router is not giving speed above 10 MBBS since new purchase till now i am running it like this.

I set up WiFi extender RE550. I entered my WiFi BT Details in WiFi and extended WiFi sections But my 5GHz light is not on and the Internet output is not happening. Anyway I think the setup is not comp