I'm making a table specific website. I added an apple touch icon to the header like so:

<link href="/images/touch-icon.png" rel="apple-touch-icon">

So when a user adds the web page to their home screen, it uses my icon which looks like a real app icon, instead of a minified screen shot of the page, which looks like nothing really.

I'm testing with several iphones and three older iPads. The iPhones work fine, but only one of the iPads is picking up the custom icon. Two of them will not. I keep reloading. I close the tabs. I force quit safari. I restart the device. Still it won't pick up the touch icon, it still uses a preview 66% of the time.

What is up with this? Is there some way to do a FORCE reload? Well, a SUPER-FORCE reload? To get it to try to find this icon again?

Note - I only have one icon size, and it's 512x512. The detail in the icon isn't all that fine, so automatic downsizing as needed will be just fine.

And as a followup question, is there a way to set a custom default name for this web app aka web clip? It seems to be using the HTML title of the page as the name. Which is ok but I could pick a better one.

I am using a real, valid certificate, not a self signed. Also nothing here is password protected in any way.

The iPad that works is on iOS 10.something, the two that will not work are both on iOS 9.3.5

Yes I know both OSes are old but those are the free ipads I have to test with and nothing I'm doing on this site is particularly advanced, feature wise. Its basically just a page with larger elements that are made for/easier to touch.

Anyhoo, the touch icon something that iOS 9.3.5 simply doesn't support? Hrm google tells me this should be working all the way back to iOS 1.1.3. I'm stumped.