I know you’ve explained the reason, but just to reinforce, each browser can operate in a different way, so there are TAGS correct for each this ranging from computers to smartphones.
I searched and saw that it is necessary to create two files both with 32x32 px being one in ICO format (Converted and not saved by image editors) and another PNG:
<link rel="icon" href="favicon.png" type="image/png" />
<link rel="shortcut icon" href="/favicon.ico" />
To avoid CACHE I advise changing the name of the files because your browser may not understand at first.
There are also the tags for other various browsers, mainly smartphones that I will put here if these do not solve your problem.
Use this online converter if you want to generate all the required formats in an automated way:
https://realfavicongenerator.net/
(It also generates all the tags needed for your HTML header)
Here it shows.
– Sam
DVD on all tested pcs did not appear, too weird this
– Pedro Cordista
Here it comes.
– Diego Schmidt
Replace "image/png" with "image/x-icon"
– Sam
It also shows... Maybe it’s just cache... Try updating the page by pressing CTRL+F5
– bio
I tried to update with CTRL+F5 but gave anyway, I do not know if it is my computer, but in yours is showing, but in the staff that I have to deliver the project, it does not work =/
– Pedro Cordista