Kind of everything else. I was working with a team from Poland and nearly everything about it was awful. The time zone difference meant waking up to dozens of poorly communicated, yet very adversarial slack messages and emails daily. A certain member was outwardly aggressive towards me on numerous occasions (one time he asked if I was mentally handicapped on the client company's jira comment section - perhaps not quite acceptable behavior?) and on each occasion I made it known to my manager, and eventually the president of the company what was going on. They did not appear to care & they did ostensibly nothing to resolve it. Now I see their job ads call for candidates who can handle themselves professionally. Maybe they've learned from the experience. I eventually quit wondering if I even wanted to remain in the software field. I've since found a role on a team of fully functioning adults who can communicate and collaborate maturely, even delightfully, and as a result I'm thriving.