WD EXT HD reformat problems with Time Machine

Ext HD reformats correctly to journaled on Monterey 12.5 but switches back on its own to APFS when used on time machine to read only.

Macintosh HD volume mount point is (Read Only) APFS Volume Group

Hi @Aruba99,

Have you opened a Support Case? If not opened, for more information, please contact the WD Technical Support team for the best assistance and troubleshooting:

Macintosh HD is the storage drive volume where macOS files and apps are stored. The volume is read-only, and the Mac user cannot create, delete, or edit any system files. Whereas, Macintosh HD Data is the storage drive volume where Mac user data is stored. The volume has read-write access, enabling Mac users to manage their files.

Further, when your external drive or any storage drive shows up as “Read Only” on your mac, then you might be encountering a very common problem with the hard drive. In such a situation, the user can open and view the files on a drive but cannot copy or move files to the storage drive. The possible reasons for this issue could be:

  1. External drive is NTFS formatted
  2. Disk permission changed to “Read Only”
  3. External drive is corrupted

However, the issue can be fixed using the below DIY methods:

  1. Reformat the external drive
  2. Change/Ignore permissions on an external drive
  3. Repair external drive with disk utility’s first aid

Hope this will help you fix the issue!