Hi @andrebraselmann,
Sorry that you ran into issues here!
When you directly modify the theme, any changes you make to it must be manually moved by you to any updated versions. That’s the nature of ANY WP theme or plugin, unfortunately. WordPress completely deletes the old version on upgrade and installs a new one. We have no way to change that mechanism directly.
However, we have a number of SAFE ways to make changes to themes that we document here:
https://docs.businessdirectoryplugin.com/themes/customization.html
These involve placing certain template files in a “safe” location that is not overwritten on upgrade. These templates will override the existing ones, if placed in the correct location. That’s the recommended method for making changes.
If you change files that are NOT included in the list of “safe” ones, then you must make those changes on each upgrade.
I hope that helps.
Please let me know if you have any other questions or issues.