body search doesn't work for message moved into folder?

[jikamens]

I have Thunderbird 45.4.0 on Linux, and Expression Search 1.0 dated 4/28/2016.

If I either move a message from another folder into my inbox, or I drag-and-drop an EML file from my desktop into my inbox, and then I try to do a search for a word in the body of the message, expression search doesn't find the message.

The same message is found by expression search if it is in my inbox because it was emailed to me.

Searches on the sender, recipients, or subject of the message work just fine; it's just the body search that doesn't work.

If I repair the folder, after the repair the body search works.

The messages in question do show up in a Thunderbird global search; they're just not showing up in expression search results.