Restore data of a specific app from a TWRP backup

Thanks to @alecxs and @Izzy I realized that the problem was related to the folder and subfolders attributes (permissions, owner and groups).
I will tell you what I did to restore just a specific application from the NANDroid backup generated by TWRP (without using any command but root is required)

1. Add .tar to the .win000 and .win001 etc (ignore the .sha2 files and any other files)

2. Extract everything in the same folder using WinRAR or any similar software


3. Go to \data\data and copy the folder of the app you want to restore to the internal storage of your phone (for exemple com.exemple.idk) and remove the cache folders from inside this folder (IMPORTANT)


4. Install Solid Explorer File Manager from the Play Store


5. Install the app(s) you want to restore from the Play Store too


6. Using Solid Explorer copy everything that's inside com.exemple.idk and navigate to /data/data/com.exemple.idk then paste everything


7. Now select the cache folder FIRST and select all the folders you just pasted one by one! DON'T use the select all button! > Click on the 3 dots > Properties > Attributes (You should be able to see a similar screen with similar permissions)

8. Now just check Recursive ☑ in both checkboxes and apply both.

Et voila! The application should be now restored to its previous state, if not uninstall it and try again step by step carefully.