Hello @tobiasgrimm,
After exporting to a CSV file, you should be able to import by clicking the import button you show in the image and then selecting the file you exported erlier:
Press the import button:

Press the "Browse..." button and search for your file

Select the file you have exported previously:

Once selected click finish:

You will see the modified values highlighted in yellow:

Let me know if you can follow the steps described above or if you encounter any error.
PS: I am not able to see the files you mentioned as attached.
Alejandro