Original website favicon persists on iPhone and iPad favorites

iOS 26, iphone 15.

I removed all content from a domain I own. All of it. Complete crash and re-build. The server was wiped clean.

I built a new site from the ground up.

All the pages have properly working favicons. All of them. Desktop / tablet / phone.

When you save to home screen, they work 100%. When you view on any desktop browser or tablet tabs they are 100% proper.

HOWEVER,

If you attempt to "add to favorites on ipad or iphone---the original domain favicon persists on the iphone and the ipad.

The files at the domain are gone. 100% gone.

I have even made a test folder on my server with "testy.php" with oddly named favicons like 16.png, 32.png, and touchy.png.

ALL of those work flawlessly.

But if you go to testy.php and try to add it as a favorite on iOS, THE ORIGINAL DOMAIN favicon is back.

How on Earth can I purge that cache from my ipad and iphone?

I have:

removed all website data;

removed cdn-apple;

cycled the favorites toggle;

cleaned all favorites that relate to the original domain off the site;

re-booted my phone more times than i have since it was purchased.

In fact, one device had only visited the site and did not "favorite" anything. That device is still plagued by the domain's original favicon.

I have spent 5 hours trying to purge this thing.