I have the same problem. All directions are in english. I urgently need a solution and I ask you to fix this problem quickly! It has now been over 4 weeks since you said that you are working on a solution.
Link Screenshot: https://d.pr/i/U9hyYy
It appears that WordPress is detecting that the language files from the repo are not present, and therefore downloads them again.
Could I kindly ask you to copy the relevant language files from wp-google-maps/languages into the languages/plugins directories. The language files to copy are the ones that have the language code of the language at the end of the file.
If you have any trouble with this, please let me know and I will be glad to assist you further.