There are very many questions on here about the authenticity of the Qur'an, how it hasn't been changed, and many good answers. But, like any religion, there are diverse opinions on almost any point. I haven't, however, heard of or been able to find any sect that states the Qur'an has been changed or updated. It seems to be a universal belief that it has not been changed.
Are there any (or were there any in the past), and if so, what reasons do they give for their difference of opinion?
Any help is much appreciated.