Hi there, from my perspective, I would like to give the entire drive erasing a try. Follow the steps to complete such a task:
Step 1: Hold down Option-Command-R at startup; this will boot macOS Recovery Mode over the Internet.
Step 2: When the main Utilities window appears, select Disk Utility and continue.
Step 3: Click the View button, then select Show All Devices.
Step 4: Eject and disconnect any external drives to avoid accidental erasure.
Step 5: Select the top level of your internal drive and click Erase. Format as follows:
- Name: Don't leave it Untitled. The default name is Macintosh HD
- Format: Mac OS Extended (Journaled)
- Scheme: GUID Partition Table or GUID Partition Map
If you don't see the Scheme option, you haven't selected the top level of your internal drive.
Step 6: Click Erase. When the erasure is complete, quit Disk Utility.
Step 7: Select Install macOS and follow the onscreen instructions.