HELP Uploading causes Slow internet

[#1]

Whenever uploading to the internet, say for youtube... the internet slows down dramatically for everyone in the household. I have even tested the Ethernet and that is slow... This did not happen with my previous ADSL ISP. I am using the plusnet router. Can you please fix this thank you.

[#2]

Apart from checking that your upload speed is the about best your line is likely to be capable of, there may not be much that Plusnet can do about this.
Uploading slowing down other things tends to happen because a large queue builds up in the router (bufferbloat). Solving the problem requires either the router to keep the queue small, or apply some kind of active queue management / QoS on the upload. If you still have the router you used on your previous ISP, and if it's not locked to that ISP, then you should be able to enter your plusnet details (yourusername@plusdsl.net and password) into it and use it on Plusnet.

[#3]

ejs has explained it very well. If you're saturating the upload this can cause issues on the download, there are ways to restrict this with external tools and some programs.

[#4]

I tried the other router (DSL-2780) but the speeds are slower. Is there no way to stop upload saturation on the SAGEMCOM 2704n which seems like an easier thing to do than figure out how to speed up my other router
EDIT:
just installed Matty123123 firmware which has QoS settings... not sure how to set it up... I just enabled it, is that enough?

[#5]

OK I am now thinking of buying the TP-Link N600... will this router solve the problem.
Is there any other low budget routers you suggest

[#6]

You'd be better asking Matty123123 on that thread as I think he's keeping an eye on it. Difficult to keep an eye on all other threads on this forum , I've only stumbled across this by accident.