My colleague pointed out that I was being seen as a negative person; to the point the boss may be considering keeping me part of the team. It was because I was pointing out the 'obvious' flaws in the proposed solutions.
Once I had the insight that my method of delivery was flawed, I changed to show I was 'on board' and THEN found subtle ways of bringing in questions about the project.
It seemed to work and was a lot more constructive.