Issue indexing pictures from Ext4 filesystem

I’m running plex on a raspberry pi2B.
I’m using gphotos-sync from to sync Google Photo with my local system.
This creates symlink to picture files to reproduce albums.
Pictures files are on an Ext4 filesystem and accessed by Plex via mounted volumes.

When Plex tries to index those files I have a WARN for each image:
Exception caught reading modified time "/data/pictures/GooglePhotos/albums/2018/0919 - Trip/IMG_20180909_165959.jpg" (boost::filesystem::creation_time: Function not implemented: "/data/pictures/GooglePhotos/albums/2018/0919 - Trip/IMG_20180909_165959.jpg")

Any suggestion?