Lightroom mobile storing album locally does not seem to work

Hi Markus

Did Lightroom Classic finish syncing?   If not, getting that fixed that may help Lightroom Mobile sync more smoothly.  If your desktop Classic app is still stuck, we'll get help to sort that out.

Another thing I wonder re-reading this thread: how much free space is on your device?  Even when configuring Lightroom Mobile to only download proxy images instead of original images, with 10,000 files this can still take lots of storage on a device.  

I'm just curious -- is there a reason for enabling Store Locally on Lightroom Mobile, versus simply allowing the mobile app access files in the cloud when needed, "on demand?"  Do you need to be able to edit thousands of photos while your mobile internet access is offline? 

Unlike Lightroom Classic which only syncs specific folders you choose to cloud storage, Lightroom Mobile will always sync all files that are uploaded to your cloud storage.  To minimize device storage used, the mobile app only download what it needs to as you navigate around your account (small thumbs for grid views, large thumbs when walking from image to image, proxies from Classic you have chosen to sync, and proxies or originals from other LR Mobile apps that will always sync). In case it helps, I just wanted to be clear that Lightroom Mobile doesn't need or expect all files to exist locally the same way Classic does.  As long as your Lightroom Mobile device has internet access, accessing images in your cloud storage to edit, organize, and share should be as smooth as if the original files are already on your mobile device.