Hello @Guadagnino74, I have also faced this.
The exact problem is that when auto backup is on, the thumbnail and previews are generated by mobile device hence heic photos work fine
but when uploading directly to My Cloud Home device, be it either by uploading or transferring it doesn’t work because the device does not support heic format
I have addressed this problem in: Ideas for WD for making MCH better
Unfortunately, WD never listen.
And I will recommend that we should buy a different NAS altogether and reuse these hard drives
