Plusnet Hub One 2.4 & 5GHz SSID configuration problem

[#1]

My five years old Plusnet Hub One router stopped working on Monday 31st October. The system tests into the home and to the router showed no fault  so a technician was booked to come next day.  The technician came, did a hard reset on the router with a pen push in the slot and left with a vanilla setup showing the BB functioning.

I tried to configure the router to the state before the fault when there were separate SSIDs for 2.4 and 5 GHz. However as soon as I applied the change for 2.4, the configuration webpage on 192.168.1.254 lost its connection to the router and remained so for any device indefinitely irrespective of connection to the router through an ethernet connected cable.

 I thus had to revert back to the vanilla install with the same SSID for both GHz frequencies.  I would appreciate any advice on where I’d gone wrong.

[#2]

I'm not too sure, but I think you leave the 2.4gHz as is and amend the 5gHz one - there is a sticky at the top of the Router board, IIRC, or maybe @Baldrick1  can help?

[#3]

@raj-18 

As @jab1 indicates, you don’t need to change the 2.4 GHz band. See here https://community.plus.net/t5/My-Router/2-4ghz-and-or-5ghz-best-practice/m-p/1351966#M840

[#4]

Thank you @jab1 and @Baldrick1  for your replies.  I had separate SSIDs for 2.4 and 5 GHz before the hard reset and the consequent vanilla reversion.  I will attempt at a convenient time  to configure again. The hub page for wireless 2.4 GHz configuration does say connection to the page will be lost.  

[#5]

@raj-18 on the picture you have posted , select the 5GHz tab, not the 2.4 one.

[#6]

@raj-18 if you change the 2.4Ghz wireless name you will change both the 2.4 and 5 Ghz as the 5GHz shares the 2.4Ghz name.

As John says change the name of the 5 GHz.

Change sync with 2.4GHz to no and change the 5GHz name to your choice and apply