Attached photos show "spinners"

I am using Joplin (1.0.152, 1.0.252) from multiple devices (Windows, Linux, Android) all synced to a private NextCloud instance.

I have a note with five photos (.jpg) attached.
Two of the photos, which were attached first, are displayed fine in the “rendering” pane.
The other three, which were added later, display as “spinners” forever in all three Windows, Linux and Android. These photos are not very large, ~300k each.

I see the resource corresponding to the last three photos (based on their resource ID) on Nextcloud.
But I do not see them in C:\Users\my_user.config\joplin-desktop\resources (Windows 10.)

I turned on debug logging and do not see anything in the log regarding these resources nor any errors or warnings.

Any suggestions how to resolve the issue?


I used the resource files in NextCould to recreate the original photos and “fixed” the problem by attaching them again.

Would still like to understand what might have happened.