I noticed that it is not possible to import the sticky notes from Mendeley in NVivo. I have to create the sticky notes as annotations if I want to import them in NVivo. Also, it is not possible to bring in the highlighting I made in Mendeley to NVivo. I consulted the NVivo support and they kindly confirmed that, at present, the features I mentioned above are not available in NVivo 12. In fact, they said these features are not possible from any other Reference Management software not only from Mendely.
I think this is a huge downside of NVivo 12; I know many of us using it would find these features really helpful. I hope something can be done about it soon. Thank you.