SQL 2012 patching failure – The language of SQL Server instance MSSQLSERVER does not match the language expected by the SQL Server update

I’ve picked up the support for a SQL 2012 instance on a server at our German site and need to apply SQLServer2012SP4-KB4018073-x64-ENU.

The patching is failing with the installer showing error "The language of SQL Server instance MSSQLSERVER does not match the language expected by the SQL Server update. The installed SQL Server product language is German (Germany) and the expected SQL Server language is English (United States)."

The server properties general tab (in SSMS) shows Language German (Germany), but the SERVERPOPERTY(‘LCID’) shows 1033 (US_English). The registry entry shows 1031 (German) as the install language (https://www.sqlserverscience.com/basics/localization/language-used-sql-server-binaries/#comment-191) enter image description here

Trying to use the German patch file SQLServer2012SP4-KB4018073-x64-DEU results in “This SQL Server setup media does not support the language of the OS, or does not have the SQL Server English-language version installation files. Use the matching language-specific SQL Server media; or install both the language specific MUI and change the format and system locales through the regional settings in the control panel”.

Any pointers as to a way forward so I can apply the patch?