Fibre Broadband - Download Speed

Help/Advice I have fibre broadband from Plusnet and use their Sagemcom Hub One. The Hub manager shows the DSL line is operating at almost 40Mbps down and almost 10Mbps up. This has been confirmed by Openreach.
When I use a line speed checker I am getting results of approximately between 19 and 20 download and between 9.5 and 9.7 upload. I have used three different line checkers - BTW , Speedtest.net and one on the Which site. The first two give very similar results.
I have run the line tests with a single desktop PC connected by ethernet cable, also with a single WiFi device, an iPad. Have tested using an Android phone and tested middle of the night, early morning and evening but the results remain consistently the same.
Looking for a reason or cause for the download speed being so low - any ideas?
Thank you for any advice you can give.
(Note - I am not overly technical.)

Run this test https://www.thinkbroadband.com/speedtest and when its finished click the results page button and paste a copy of the URL for that page so people can see the results.

It is about seeing if there is an obvious difference between the two download tests and whether speeds vary or are hitting a maximum value all the time.

Thank you for the advice. A link to the results of my broadband speed test performed this morning -
https://www.thinkbroadband.com/speedtest/15836640095...

Thanks

You also get faster upload speeds sometimes e.g. http://tbb.st/1582798744293033455 and http://tbb.st/1582798630210985155
there two faster upload speeds also happen when the average latency for small packets is lower 49 and 47ms.

The lower upload speed test and others have latency in the 111 ms to 165 ms region. There is a green Analysis button on the results page, a screen shot of what that shows might help i.e. compare a test where the average was low and the average was high.

Are you 100% certain that no devices are downloading or uploading (more likely upload) across the connection e.g. kids on youtube, iphone uploading a large video to cloud or or ther things.

The download looks stable and flat, suggesting that it is hitting some limit, this might be a configured line speed setting on the Plusnet side of things - there used to be a way to see this in the account portal but left Plusnet 3 years ago and have forgot where it was.

Maybe here. That's where it was years ago.

This does look like the PlusNet "Current line speed" issue, you can view this in your account under the Broadband tab giving a list of estimated speeds and at the bottom, the current line speed. It can get stuck on 21Mbps, which is some legacy speed cap for ADSL2+ services giving a throughput speed of around 20Mbps.

Customer support will probably not have clue or say it is no longer used since PlusNet changed their network a few years back, but it can and does affect some customers. It is known to affect users who have purchased a static IP address because of the way they connect to the network. However I believe there have been cases recently where users on dynamic IP addresses have suffered the same problem.

It may be worth posting on the PlusNet forum, you will get better technical support, but they are bit slow to respond lately.

In reply to a post by RobertoS:

Maybe here. That's where it was years ago.

Generally stopped working before I left PN in Sept.

Looks suspiciously like a device is uploading to a backup service, eg one drive / BTCloud / Google etc

In reply to a post by jchamier:

In reply to a post by RobertoS:

Maybe here. That's where it was years ago.

Generally stopped working before I left PN in Sept.

I was vaguely remembering this more recent thread, but couldn't check it out of course.

The description given there looks remarkably similar to what RealAleMadrid posted a little earlier here .

I�ll check my family�s line, they�re still with PN.