Thanks for the explanation!
Another question for you: I’ve got a database synced over iCloud that is .dtSparse on my iMac, and .dtBase2 on my MacBook Pro. Is that normal?
I thought I set up encryption when I created the database a while ago, but apparently it’s only encrypted on one machine?
Yes, it’s normal and by design.
If you want the database encrypted on both Macs, you need to import the database as an encrypted database from the sync location.
You can delete the unencrypted one and reimport it via the action menu under the Databases list in Preferences > Sync.
Note you will need to specify the proper size and encryption key on the receiving machine. This too could vary but it’s likely less confusing to make sure you’re using the same spec for both machines.