@Shanky2201 

From what I can see in your screenshots, your Internet connection has dropped briefly and then recovered.

Call your ISP and ask them if they can advise on that.
Since you're with static IP address on the Internet port, the only thing you can do there is adjusting the MTU size (if that's the reason for these drops):

If you want to experiment further you can start lowering the default 1500 value and test if that will stabilize your Internet port connection:

1480 (save>reboot>check), if not resolved then try 1450 (save>reboot>check), if not resolved then try 1260 (save>reboot>check).

Correct. Do you still own the Tenda device you mentioned earlier ?

If yes, you could test with that to see if the connection is stable and copy all the Internet port parameters including MTU.

Then transfer these on C6 to see if that will improve things.

Try adjusting the MTU size for now to see if that will improve the stability of the C6 Internet connection.

If that doesn't help then contact the local support and explain the iInternet port connectoin stability issue.

Can you post the following screenshot (Click on circled Arche C6 icon bfore capturing):

@Shanky2201 @Kevin_Z 

What's the internet speed that you have subscribed to, with your ISP ?

Judging by the screenshot, you're not going to get more than 100 Mbps at the moment:

Your router is negotiating 100 Mbps connection speed with the ISP equipment - if you are subscribed to a faster speed, then you should show them that screenshot.

That could be also the reason for the issue you are experiencing.

As for the MTU there's no point to go bellow 1260.