Encrypted notes on shared notebook, works on mobile but not on desktop

Operating system

Linux

Joplin version

2.11.11

Desktop version info

2.11.11

Sync target

Joplin Server

What issue do you have?

I recently shared a notebook with someone else. My notes are visible in her apps.
Now she added a few notes.
They show up as "encrypted" in my desktop version, but are visible in the Android app.
Of course I want them to show up in the desktop version, as I rarely use the Android app.

I noticed in the "encryption tab" that there are 4 sets of keys, and in the first column, which is labeled "active", only the first one (the oldest one) is marked. I'm not sure whether this is of relevance.

Joplin v2.11.11 is a few years old (see Joplin: Release cycle) and doesn't support Joplin's newer encryption methods. Upgrading to a newer version of Joplin may help.