Music files stored on MyCloudHome are shown incorrectly in SONOS app

My music/video files are stored on MyCloudHome. I activated PLEX service on the MyCloudHome device. To be able to play my musics on a SONOS speaker, I added MyCloudHome as source to my SONOS app.
At this point I had to realize that a lot of songs were wrongly categorized (unknown or wrong artist, unkonwn album).
Now I corrected all the EXIF data on my mp3 files. On a PLEX client looks everything fine (correct artist and album information), but in the SONOS app it is still wrong.

Any idea how to actualize EXIF data?