Hello Khurram, welcome to the Microsoft community, I'll be happy to help you today;
I understand that Edge is losing saved passwords on every launch;
Usually, when this type of problem occurs, it means that your Edge profile may be corrupted;
In that case I suggest you try the solutions provided in the link below:
https://www.makeuseof.com/fix-microsoft-edge-no....
Disclaimer: There are links to non-Microsoft websites. The pages appear to provide accurate and secure information. Watch out for ads on websites that may advertise products that are often classified as PUPs (Potentially Unwanted Products). Thoroughly research any product advertised on websites before deciding to download and install it.
Verify that the passwords are now saved;
See you soon!