Unexpected behaviour using Dropbox to sync Logseq

I have 2 Macs, dropbox, and Logseq. All software is updated to the current stable versions.
The Logseq folder is in my Dropbox.
This folder is set as “available offline” on both Macs, which ensures local copies are made.

I’ve noticed the following unexpected behaviour.

Say, on Mac 1, I check off some todos. Everything works as expected. Then I quit Logseq.
Then I go to Mac 2.
I make sure Dropbox thinks everything has been sync’d on Mac 2.
Then I fire up Logseq on Mac 2.
The tasks I’d checked off on Mac 1 are NOT checked off on Mac 2.
If I then quit Logseq on Mac 2, and restart it, the checked off items ARE checked off.

Has anyone else noticed this or similar behaviour?
Has anyone got any ideas why this might be happening?