2.4GHz Speed Issue

[#1]

Good evening,

First up and in the interests of full disclosure, my teenagers have a far better grasp of all things internet/wifi than I do and technical terms will go wayyyy over my head.

We have both 2.4GHz and 5GHz enabled on our router. Okay so the aforementioned teenagers are getting a little fed up because their phones (although only a year old, not 5GHz compatible) are really struggling to use the 2.4GHz simultaneously. Upload speeds are unmeasurable and download speeds are barely there if both are using their phones at the same time. 

Surely both 2.4 AND 5 should be able to work at a suitable speed for both phones at the same time? Any advise on how to proceed would be gratefully received. Thank you in advanced.

[#2]

Do you witness same problems when both phones are in same room as the hub ?

If you have android phones, use wifi analyser to find out how bad the wifi congestion in your neighbourhood. 

https://play.google.com/store/apps/details?id=com.farproc.wifi.analyzer&hl=en&gl=US 

Try manually changing the wifi channel number to 1, 6, or 11 on the Hub One.

https://www.plus.net/help/broadband/router-user-guides/ 

If problem persists, there may be a faulty device (phone, hub) or wifi compatibility issue.  Only suggestion would be to try a completely different model of wifi router to see if there is any improvement if you cannot persuade Plusnet to send you another hub one to.  eg. BT smart hub 1 (choose the 2016+ model, not the newer hub 2) are cheap to purchase on ebay.

[#3]

@Smash1 

At the very best your wireless speed will not be as good as you get with a wired device. So what speed do you get with a computer connected to the hub using an Ethernet cable?

[#4]

I don't own an Ethernet cable but when only one of their phones is connected, the DL speed is around 37MBps and the UL is approx 9.12MBps (which is on a par with the 5GHz). It drops dramatically when the second phone is on wifi. All other devices have been already been switched to auto connect to the 5GHz.