I don’t think the case issue is just about thickness. Even a thin case may be enough to cause an issue. I think the bigger issue is the type of case - some are built specifically for wireless charging such as the magsafe cases from Apple. They have a coil built in to help with wireless charging.The factory charging pad seems very hit and miss with an iPhone pro max. Mine didn’t work with a very thin case. The Jeda pad fixed the issue.