Comments and annotations not saving in adobe reader after re start

Im a student I read my subject text books on adobe . After I annotate and comment in the pdf and close the app those are not saved after reopen it. Imagine u read for hours and underline stuff after understanding the concepts and simply goes waste due to tech issue it's very frustrating. This same issue has been raised by few other adobe users . But u guys are reluctant enough not to set this right. Don't u think time and effort are valuable. How can u ignore such a imp thing. May be it's time u correct this issue . Or else I thing it's time to ppl like me to leave the adobe family and look for some reliable alternatives who will at least listen to us.