networking – Speed from mobile hotspot is not consistence and poor speed

I am WFH and using Xiaomi note 8 pro for hotspot to my work computer and I have D-Link dongle which catch the hotspot signal. I am using Airtel sim card for that.

When I start working to my system at 10:30 IST in the morning, sometimes I do get speed about 15-20Mbps but while loading the page it doesn’t seems to be that much speed. After 2-5 minutes of this “Rocking” speed, it came down to below 100Kbps and sometimes below 10Kbps as well.

If I am opening, I can watch the videos in full HD without buffer but at the same time i won’t be able to remote connect to my PC.

Same when i open youtube, facebook, instagram like app on my mobile, it works good and speed is also good as i can see the speed at the top of my screen. Youtube is giving me speed like 600Kbps-1Mbps and other app too gave me speed of upto 500Kbps. But as soon as i opened some other app, speed bites the dust.

Suppose I opened 2 apps in the background. One is Youtube and other one is cricbuzz. I maximize youtube and browse some videos and i can see speed upto 600-800 Kbps and suddenly i minimize the youtube and maximize cricbuzz. All of sudden the speed from 600Kbps goes down to 6Kbps.

I am unable to work properly and neither i am getting any support from Sim Company. I am asking this question over here so that if i could get some help in terms of if this is the issue of network company or mobile company or my device is not upto the capacity.

If there would be any work around or hacks. Any kind of solution would be a great help.