Okay, so there is a known issue with Microsoft installing different versions of databases, try this from the installer instructions:
Installing SqlLocalDB will upgrade any existing older version, due to a bug in the setup routine from Microsoft this may cause an issue. If there are problems starting the DvrOnTime service please use the Registry Editor and check the following key:
[HKEY_USERS\.DEFAULT\Software\Microsoft\Microsoft SQL Server\UserInstances\{A Guid which
varies by machine}]
Check the value for ParentInstance, this should be: MSSQL15E.LOCALDB and if not, it may be left at a
previous version, for example showing 12E or 14E, edit this to have version 15E and try and restart the computer and try again.
So if you found that key needing changing, have another go with the installer.
Installing SqlLocalDB will upgrade any existing older version, due to a bug in the setup routine from Microsoft this may cause an issue. If there are problems starting the DvrOnTime service please use the Registry Editor and check the following key:
[HKEY_USERS\.DEFAULT\Software\Microsoft\Microsoft SQL Server\UserInstances\{A Guid which
varies by machine}]
Check the value for ParentInstance, this should be: MSSQL15E.LOCALDB and if not, it may be left at a
previous version, for example showing 12E or 14E, edit this to have version 15E and try and restart the computer and try again.
So if you found that key needing changing, have another go with the installer.