I have never seen Startup Disk represented like in your Edited Image below
But then again, I have not seen everything
To avoid the question / answer and question answer scenario
Suggest the User starts with the Top Suggestion and test.
Thereafter, move down to the next and test again.
Keep on going in the Order that they have been presented or until you reach the Final Suggestion
Restart in Safe Mode. This will perform a Disk Repair, clear cache files and only load Apple Software, extensions and fonts. The boot up will be slow and can take some time - Normal.
Safe Mode will also eliminate Third Party Software, extensions and drivers from loading. It will only load the Minimum amount of Core Apple Processes to allow the the computer to function at a reduced Level of Performance
Does the issue present in this mode ?
Sometimes a Safe Boot followed by a Normal Boot will just put things right.
If not - there could be something in the main User Account playing up. To further isolate this - Set up users, guests, and groups on Mac. Then log out of the Main User account and log into the dummy account and test again if the issue persists.
If the issue is present in the dummy account - then, this appears to be a System Wide issue on the computer.
Download the Application Etrecheck directly from the Developer.
The Application is Not a " Silver Bullet " and is only a tool to examine the Hardware / Software used on this computer
This is a Diagnostic Tool that makes no changes to the computer Hardware / Software used on this computer
The application is free or paid from added features.
The Report will Not Reveal Any Personal Information.
Post back the Full Report - copy and paste - >>>> using the Additional Text Icon ( 3rd Icon to last ) <<<<
Using EtreCheck
