Imported xslx file notes have timestamps

This issue is unique.

[X] I have used the search tool and did not find an issue describing my bug.

Operating System

Windows 10 / 8.1 / 7

Version information

8.0.1

Expected Behavior

MS Office and Google Docs have a "Add Note" feature that adds a "postIt"-type comment without a timestamp. When opening such files in OnlyOffice, any note SHOULD converted to a "comment thread" where:

the note becomes the first comment and never gets a timestamp

Example, where I reopen the file in MS Office:

Actual Behavior

MS Office and Google Docs have a "Add Note" feature that adds a "postIt"-type comment without a timestamp. When opening such files in OnlyOffice, any note is converted to a "comment thread" where:

the note becomes a "comment" timestamped to the time the file is openened each time
editing this "comment" does not change its timestamp on edit or document save
commenting in that thread will always show this "comment" as newest each time the document is opened (causing confusion since no new comments were added by anyone since the last time it was closed).

Example, from current build:

Reproduction Steps

Create XLS document in google docs or ms office
Add a "note" to a cell (not a comment!)
Save this file and reopen in OnlyOffice
Note the timestamp on the "note" (TS1)
Edit the "note", reply to the "note" (note those times as TS2 and TS3, respectively)
Close and reopen the file after a couple of minutes
Notice the "note"'s timestamp has changed to current time (when you opened the file) and that this time is always larger than TS1, TS2, and TS3 every time you open the file.
Notice the comment button in the left menu has a yellow icon saying you have new comments. This is not true.

Additional information

No response

ONLYOFFICE / DocumentServer