Download speed slow when uploading

[#1]

I am a fairly new signup, coming from Sky. My general upload/ download speed seems OK and comparable to Sky when I run a speed test, maybe a bit slower, but I have noticed that if I am uploading something such as doing a backup to Dropbox, the download speed drops drastically, virtually to nil. I did not get this on Sky. 

To put in context, a webpage that opens in seconds might take around a minute to open, when the uploading is going on. 

Does Plusnet "throttle" downloads whilst uploading? Or is this a glitch that technical support can look into?

Thanks

[#2]

Hi there.

While we don't throttle your speeds in any way and line tests aren't showing a definitive cause for the problem, we're seeing you're on a 3dB SNR target set by the dynamic line management(DLM) software at the exchange.

DLM would generally work in a different way compared with Sky as they'd likely use their own equipment at the exchange as opposed to the BT equipment we'd use.

I've made a change to the SNR target by increasing it to 6dB, which should complete within the next 30 minutes. Let us know if you're still experiencing problems afterwards.

[#3]

Thank you, I will review and let you know if any further issues. 

[#4]

If you've switched to the Plusnet Hub Zero (Sagemcom 2704N), then it's a problem with those routers (bufferbloat).