Just see the difference after disabling the 2nd sim

This is the issue i'm facing since very long. Most of the time even after disabling the second sim won't make any difference i have to put my phone on flight mode several time, and when i'm using hotspot i need to make sure my phone's screen is on otherwise i am unable to access the internet.
Sometimes when i'm using YouTube the internet gets disconnected and for that i have to put my phone on flight mode then it starts working and yeah, both upload and download falshes in the status bar.
This discussion has been closed.
Comments
HI,
Try a different SIM or try swapping SIM.
Run SMMI test to check if this is related to hardware
How to Enter SMMI_TEST (test hardware)
Go to Calculator=>type " .12345+= "
you will be entered to SMMI_TEST
Update your phone's software to latest version if not.
Last step would be:
Kindly visit the nearest service center:
https://www.asus.com/in/support/service-center/india
Sim is working fine on another phone, but swapping the sim is nightmare, I can't even send a whatsapp message.
I am using the latest version of software and SMMI_TEST passed even after swapping both sims.