The most egregious bug/s I've encountered in recent years is the utterly cursed tab management in iOS Safari. A couple of times a year it will just nuke all my open tabs (450-500) and present me with a delightful blank screen. Before that it will mislabel the active tab group on and off before giving up entirely. Quick action on my part stops the destruction syncing & I usually end up recovering them on my Mac & then…
Safari iOS: Be on a page, tap hold a link, click Open in new tab, go to new tab. The Back button should be grayed out and isn’t, and clicking it closes the tab.
Chrome iOS: Be on a page, tap hold a link, click Open in new tab, go to new tab. Back button correctly grayed out as the tab has nowhere to go back to.