Comments lost

We have been editing reports and publishing them to the online work space, overwriting the existing versions. We leave each other comments on the published online versions so we can identify and sort out any issues. One team member recently edited a report and published it, but when they went to the online portal to view it, it tried loading for a long time and then came up with an error message. They then tried publishing it again, and when they went to the online portal to view it, it loaded up but all the comments had been deleted, with no obvious ways to retrieve them. This happened again today on another report and is causing problems, so can someone tell us why we are losing our comments? Additionally, is it possible to donwload comments offline as a safety precaution?

Thanks,

Toby