Sadly I find it happens more and more often, even with important things like financial services.

What I haven't figured out yet is whether it's really the Firefox engine that is the problem or just that Firefox also provides better tools for blocking obnoxious trackers and the like. Maybe because I have those tools turned on by default more sites using obnoxious trackers break in Firefox than other browsers. In most cases that is a feature not a bug but it's frustrating when essential functionality on sites providing essential services gets broken as collateral damage.