4GEE WiFi mini MBB / internet on Wi-Fi, update and other issues

[Olexandr]

My 4GEE WiFi mini MBB  (EE40VB-2AE8GB3) stated to behave strange:

1. It fails on update check (it might not appear critical, but previously it used to work, and message was that it is up to date)

2. It doesn't show working/connection time and amount of data. Values remains "0" not depending on real working time (previously all these data used to change and indicated properly)

 3. (the most critical issue) Some of my device's even though are connected to WIFI don't get Internet access and aren't reachable online (And there is no issue with the devices, because they work properly when connected to any other WI-FI)  while others are ok.  

Meanwhile I normally have internet access on my PC when connected via USB. And it appears that some other devices (PC, smartphone) also have internet access via WIFI. Sometimes main and other settings pages are loading to slow or even don't.

I tried few times  both software factory reset (through setting page) and hardware factory reset (reset button on router). nothing helps 😣. 

What else can i do? Is there any possibility to renew firmware (from my perspective it appears the issue caused by firmware not hardware)?

[XRaySpeX]

2. Visit http://add-on.ee.co.uk/status from a device connected to your mobile router by WiFi to see your data & credit status as well as its mobile no. at the top.