(I'm on support staff at Overleaf.)
It's not 100% clear from your question if you're asking about copying an entire project (often times Overleaf users colloquially refer to this as "copying the file" when in fact they are copying the entire project), or if you're copying only a single file within a project. Either way, yes, comments and tracked changes are not transferred when you copy a project or copy a single file within a project.
More broadly, when copying an entire project, the project's history, chat, track changes, and sharing settings are empty in the resulting new project. Effectively only the project's source files are copied into a new project, and the compiler engine and main file settings are transferred.
For more information, see Copying a Project: Copied Projects
As for comment and tracked change positions being lost when copying and pasting large chunks of text, or undoing/redoing changes that involve large chunks of text: this can happen in rare cases, unfortunately. Usually our system catches this and in most cases our support team can restore a previous snapshot of the comments and tracked changes.
If you'd like to see if this is possible, please write to us at support@overleaf.com with the following information:
- the URL of the affected project;
- the name(s) of file(s) in the project where you require track changes restored;
- the date and time that the problem occurred; and
- the time zone you were in when the problem happened.
We will then check our systems to see if a previous snapshot can be restored.
Best Answer
(Disclaimer: I'm a support personnel at Overleaf.com.)
If you have not saved a labelled snapshot in the "History & Versions" menu that you can restore from, there are two other possibilities.
The 24-hour File History (the clock icon just next to "Edit") can restore a file's history in the last day. Clicking on that icon will display the 24-hour history of the file currently loaded in the source code panel. (This is available across all subscription plans, including the Free plan.)
If the edits needed are beyond 24 hours ago, or an entire file was deleted, the Full History feature will be useful; see https://www.overleaf.com/help/286 for further details.
In brief: Browse through your project's Timeline or Recent Activities from the "History & Revisions" tab. If you then see an edit that you need, you can click on the view source link (before or after the change) and then on copy to copy the entire file contents at that point; or use the download .zip to download the entire project before/after that point.
The Full History is a Pro plan feature; it can be accessed by activating a free Pro trial at https://www.overleaf.com/plans if you don't want to subscribe immediately.