Active comments anchored to tracked-change deletions are permanently lost on reply/save (Modern Comments, Microsoft 365 desktop)

In a quick test, with the options for tracked changes set as indicated by the screen shot below, I can't reproduce the issue.

Are you able to share a representative sample document so that we can have a closer look?

Dear @Akshay Sachdev,

I hope you’re having a good day.

Thank you for sharing such a detailed analysis, I can see you’ve already invested a significant amount of effort into isolating the behavior, especially with the XML inspection and controlled testing (local copy, AutoSave off, single editor scenario). These are exactly the kinds of checks that help clarify whether this is a view issue or something deeper.

I took some time to review your case carefully and went through the available Microsoft documentation as well as similar patterns related to Modern Comments and Track Changes. Based on what you’ve described and what I was able to validate, I’d like to share a few observations.

From your testing, this does not appear to be a display/filter issue. Since the comments are missing from both All Markup view and the Reviewing Pane, and you’ve confirmed they are no longer present after saving, this strongly indicates that the comments are being removed during the save process, rather than hidden.

What stands out most is the pattern you identified:

• Only active (unresolved) comments are affected
• The same set of comments is consistently removed
• All affected comments are anchored to text marked for deletion (Track Changes)

From a technical perspective, comments in Word are tied to specific anchor positions in the document, while Track Changes manages a separate revision layer. When a comment is attached to content that is marked for deletion, that anchor can become unstable depending on how the document structure is processed during save.

Based on this behavior, it appears that when Word reprocesses the document (during reply or save), it may not be able to maintain a valid anchor for those comments, and as a result, the comments are dropped. However, I was not able to find any official documentation that explicitly confirms this as expected behavior.

So, at this stage, I would describe this carefully as likely related to how comment anchors interact with tracked deletions, but it may also indicate a limitation or a potential regression in the current Modern Comments implementation, rather than something that is clearly documented as by design.

To your specific questions:

1. Known behavior or bug

I was not able to find a public article or bug reference that confirms this exact behavior. Given your reproducible scenario and the consistency of the affected comments, this does look like something that could reasonably be escalated for further investigation.

2. Any setting, GPO, or registry to prevent this

At the moment, I did not find any setting or policy that can force active comments to persist when their anchor is tied to deleted content. This seems to be part of the document processing logic rather than a configurable feature.

3. Switching back to classic comments

This is a supported workaround. Microsoft allows you to temporarily disable Modern Comments in Word options. Since the classic comment model handles anchoring differently, it’s a valid mitigation to test in your scenario. I would treat this as a workaround rather than a permanent solution.

4. Recommended workflow for preservation

Based on the pattern observed, the safest approach in documents with heavy Track Changes would be:

• Avoid leaving active comments anchored directly on text marked for deletion
• Where possible, move the comment anchor to nearby stable (non-deleted) content before replying or saving
• Consider resolving or capturing critical comments before performing large edit/review actions
• For high-impact deliverables, keep a temporary backup or extract of important comment threads

I understand from your notes that you already attempted re-anchoring within the same structure and still reproduced the issue. That suggests the instability may extend beyond just the immediate text range, which is another reason this scenario stands out as worth deeper investigation.

Given the consistency of the affected comment set, the fact that it reproduces offline and your validation that the loss occurs during save, this looks like a strong candidate for escalation rather than a usage issue.

If this is impacting a client deliverable, I would recommend opening a support ticket and providing:

• a minimal reproducible file
• your build/version
• before/after comment counts
• and your XML observation

Your current analysis is already very solid and would significantly help speed up any internal investigation.

You can raise support ticket from Microsoft 365 Admin Center>Support>Help & Support.  

For reference:  Get support | Microsoft Docs   

Thank you again for the detailed breakdown, cases like this are not simple, and your testing has already ruled out many common causes.

I’m here and happy to continue looking into this with you. Please feel free to reply below if you have any update or further concern.   

Warm regards, 

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We are experiencing very similar behavior in Microsoft 365 Word and wanted to see whether you ever found a cause or solution.

Comments disappear when affected users save documents stored on our shared network drive. The comments are genuinely removed and do not appear in the Comments List or Reviewing Pane.

So far, we have confirmed:

• All Markup is selected.
• Disabling Modern Comments did not help.
• Word Safe Mode did not help.
• Signing out of Office and back in did not help.
• The issue followed an affected user to a loaner computer.
• Another Office account (on the same computer) could save comments successfully during testing.
• The problem initially affected one user and has now appeared for a second user.

Because the issue follows the user between computers, we suspect that this is related to the user’s Microsoft 365 account, roaming Office configuration, or a user-targeted policy rather than the local Word installation

Were you ever able to determine the cause or find a solution? Did Microsoft provide a case number, bug reference, affected build range, or expected fix?