The royal mail tracking website for example brings up an obnoxious full page block on top of the actual content. Only happens on Firefox on android. Chrome worked fine.

Edit: also, just for reference, I’m amazed anyone actually needs examples of this. Its very well known that different browsers have different supported functionalities and unless the webdevs are properly customising styles and scripts for different platforms their gonna deviate. Thusly its not surprising most stuff only works as designed on Chrome since that’s the only Web browser that’s guaranteed to be tested on (it has the lions size of market share, to the point Firefox barely even registers).