the favicon icons disappear from the Homepage shortcuts

I pinned 8 websites in my homepage shortcuts. After pinning, their icons were matching the websites. Like when I added Moneycontrol's website to shortcuts, its icon looked good, but after 1 day or a few hours its icon changed to "M". This has happened many times. I tried many different methods but I did not find a solution. I request you to please fix this. I really like your service, everything is good, just please fix this one thing.