Unable to save Word documents when accessing them directly from the site because the document never converts from a read-only even though the User chooses to enable editing

Question

Issue has only popped up recently and cannot reproduce in a Test environment.  Unaware of any SharePoint changes, so hoping someone can point me in the correct direction.
Previously Word document did not have to be physically checked out, but rather the editing of the doc also checked out the doc in a document library. This is the way we want it to remain –
no manual check-out process. Now if a doc is edited without being checked-out, there is an issue with the process as the application thinks the doc is read-only (message received when trying to save the doc) even if enable editing is selected. The
following message appears when you try to save the document:
  This message can appear if you have been editing a file that was opened as read-only. A file opened as read-only will have (Read-Only) appended to the file name as it appears in the title bar of Word. You can still save the document, but you must
save it by using a different file name. If you use Windows Explorer to change the read-only properties of the file, while the file is open in Word, it will not enable Word to save the file. Word must open a non-read-only version of the file in order to save
it by using its original file name. If you have not made any changes to the file, you can close it, and then use the following steps to make the file writeable. 1. Click the File tab, and then click Open. 2. Browse to the file and right-click it. 3. Click
Properties, and then clear the Read-Only check box. 4. Reopen the file. If you have made changes to a read-only file, you can save it, and then use the following steps to give the modified file the original file name. 1. Click the File tab, and then click
Save As. 2. Enter a different file name, and then click Save. 3. NOTE: Adding "Rev1", or "Mod1" to the original file name may help you to remember it later. 4. Click the File tab, and then click Close. 5. Open Windows Explorer. 6. Browse
to the original read-only file. 7. Rename the read-only file. 8. Browse to the new file. 9. Rename the new file to the name of the original file. Do not delete the read-only file until after you have determined you no longer need it.
Previously, when check-out was optional, a file was checked out automatically when someone opened it for editing, unless it was already checked out. The editing commands notified the User that the file is being/was checked out.  The real issue is the
word doc can no longer be saved as the application still believes the doc is read-only.

Answer 1

Hi, 
According to your description, you give the domain admin full control over files on the old file server, but you cannot move the files to the new file server. After pull the files from the old to the new file server, the domain admin can only read the files
on the new file server.
How did you move the files from the old file server to the new file server? Did you setup replication between the two file server or use robocopy? 
Please check the files permissions on the new file server to see if the permissions are changed, then share the folder on the new file server to everyone to see the result.
Regards, 
Mandy
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