Some websites may incorrectly identify your iOS/iPadOS Safari User Agent when used in one or other of its browsing modes - of which their are two - these being Desktop and Mobile. When operating in Desktop mode, the User Agent will declare itself as Mac computer; in Mobile, the browser will appear to be iPadOS.
It’s easy to switch between modes if a website isn’t functioning correctly. From the desired web-page, touch the aA icon at the left of the Address Bar; this will reveal a menu. From the menu select Website Settings, then select (or deselect) Request Desktop Website, then tap Done. Now refresh the webpage.
The chosen setting will be saved for the selected website - and can be simply reversed if needed.