@igloo Thank you for the tip. I almost forgot about that. I checked all my 4G phones. Only one of them has Mediatek Processor. Today it is even worse and no websites or even speedtest app is not even loading up since evening ( I notice that the worst time is from evening onwards) showing network connection issues. It is latching on to 2300 in all my phones by default even in inner rooms (last year it used to shift to band 3 and band 5 automatically in inner rooms but it is not latching up anymore to any other bands). Even my BSNL broadband is dead and so, it was particularly bad day today.
However, I tried your trick of forcing band 3 in my Mediatek processor phone (only one of the 4G phones) and surprisingly it connected to internet immediately and speedtest app also loaded. In fact, I am writing this post with Jio (although BSNL 3G is also working and is providing better speeds than even Jio band 3 . The speed is around 1.3 Mbps download and 4 Mbps upload. Although the speeds are not that great but at least it is working whereas in band 40 it is refusing to even load any websites.
These problems have started in the last few weeks and has never been the case in the last 1.5 years since I have been a Jio customer. The problem is the worst during evening hours. Do you know any permanent resolution for this issue or do I need to contact Jio and inform them about speed issues. Even webpages not opening up now is a terrible issue now. Honestly, never thought Jio would turn like BSNL or worse. Guwahati does not have any major alternate ISP. So, Jio was the only savior after which BSNL has also gradually improved their plans and services. Hence, I would still like to rely a lot on Jio.
Here is a speedtest I ran right now with Jio on Band 3. With the default Band 40, speedtest or any other websites are not even opening up.
EDIT: I am testing again at 12.30 am in the night now and band 40 i.e. 2300 which are on the other 4 phones are working again. It looks like the speed decrease was probably due to users. How many people can pull down a Jio tower? I do not live in a very densely populated populated place compared to say apartment complexes in a metro city. It is populated but not super dense. How many simultaneous users can pull down a Jio tower to make it nearly unusable? I doubt there are that many Jio users in my locality. Can the guests in my neighbors wedding pull down the Jio tower (I doubt there are hardly around 10-15 extra people max in their house due to their wedding. I doubt everyone uses internet or Jio either)