Well, I thought that @marx's answer from "Discussion about Nextgen(Israel) 9.18.27.687519 (Jan 26 2017)" to @tenshu's Q:

I used an apk from modemakias... ... Which version of nextgen israel is fonctionnal with android 11?
Quote Originally Posted by marx View Post
All!
But only installed on internal storage.
The reason for this is the system ban on using the "Android/data" folder on external memory. Neither root, nor change of owner, nor change of permissions helps.
Will do for you here too. Apparently not.