Snap downloading speed

I noticed a very strange ups and downs while downloading snaps which are big in size, I tested and can confirm the behavior remained the same at least for me.

What is happening:
While downloading big snaps for example qt513 (that is a content snap actually but that should not trigger this issues for sure) the first few chunks of download completed with normal speed that i expect from my network, but as the download surpasses 15% the download speed gets extremely slow and snapd reporting it will take ages to download the snap. After waiting for long I cancelled the install as nothing was happening (I tested my network speed and everything is working fine am getting 42Mbps downlink speed).

Also snapd keeps re downloading the app again and again by itself
ex- It reported that telegram snap is downloaded 53% and suddenly started downloading from 0% again. This happened many time during the course.

I am from India using Ubuntu 20.04.2 LTS for testing.

snap    2.51
snapd   2.51
series  16
ubuntu  20.04
kernel  5.8.0-55-generic

Let me know if we need anything else to debug this.

Thank you.