We have found a problem with all WebKit related browsers (Mac Safari & all iOS browsers) while trying to get tile layers (WMTS) that are behind an authentication. Everything is working fine with android devices and desktop browsers like Chrome, Firefox and Edge
Problem: Safari and other WebKit browsers (iOS devices) are not sending credentials/cookies with request headers. Request fails because the server/layer can't be accessed without the authentication details, which should be included with the request cookies. When using safari dev tools, the network tab for the tile image requests says "No request cookies." and e.g. request made with Chrome has all the required authentication details sent with the request cookies.
What we use:
Indicates whether cross origin requests made to the associated server should include credentials such as cookies and authorization headers
Our app is supposed to work with apple devices but this issue is making it difficult to work with, because some important layers are not being rendered. Is this a known issue or is there something we might be missing that could fix the problem?