Hey PM_Faiz,
Thanks for the follow-up. Because you’re still having issues with the microphone that records voice memos after going through those steps, the next step would be to make a backup of your iPhone and then restore and set it up as new to determine if the issue you’re having is a software or hardware issue.
First, back up your iPhone: How to back up your iPhone, iPad, and iPod touch
After backing up, restore the device and be sure to set it up as new, not from the backup, for testing purposes: Restore your iPhone, iPad, or iPod to factory settings - Apple Support
With the iPhone restored as new, do you still have the same issue with the microphone?
Cheers!