GTI interview questions

Pre-interview process was pretty good. I applied through the main GTI website, heard back promptly. I was offered a virtual interview with times and dates to select from. No issues. Interviewers were friendly and i believe they were the managers of the team i was interviewing for. Later that day I then was invited back for a second virtual interview again, no issues. This time i believe i was interviewing with actual team members. They didn't seem that well prepared as i was advised that the interview would last around 60 minutes and it actually lasted 15 at which point they had appeared to have run out of questions to ask. I was advised that i would heard back in about a week, which is standard process i guess. After a week, i had heard nothing, after a second week, still nothing. I emailed in to enquire what was happening, heard nothing back, another week went by, again nothing. I emailed in a second time, 4 weeks after my second interview, and finally heard back two days later. I was told at this point i was unsuccessful. I requested feedback following to be told in one line some of my answers were vague and nothing else. Overall, i would say the experience was incredibly poor and unprofessional.