First bug: I load JIRA and see I have notifications. I open the notifications bar and see an out-of-context comment on a story. I open the story by ctrl-clicking the title in the notification bar. When it loads, I attempt to scroll down to see the comment. The page suddenly enters infinite scroll with the comment I'm searching for at the end of infinity (i.e. impossible to read). I have to refresh to see the comment, which is the reason I opened the page in the first place and not exactly a trustworthy solution.
Second bug: when I eventually chase down the comment and start a reply, sometimes I need a reminder of the exact story I'm in. I scroll back up to see the title. However, suddenly the top of the page is defined as somewhere just below the title (the first line I can see is the Type: story). I have to refresh to see the story title, which removes my draft comment and starts the whole fun cycle over again.
My coworker has no issues with this, but I've seen this consistently for weeks.