search resuts with "from:" are sometimes incomplete

I'm running Geary from git mainline on Ubuntu 19.04.

When I search using "from:sender", the search results are often incomplete. Sometimes only a couple of results are missing, and other times I see only even a couple of results, even though there should be many more.

After this happens, if I click another account in the left pane, then click back to the original account (with the search still active), I see all matching results. So this appears to be some sort of display refresh problem. I'm not sure whether it's related to using multiple accounts.

By the way this is not a new bug: I have seen it many times over the past months, but have only gotten around to reporting it now.

If the developers can't reproduce this, is there more information I could provide to help debug this?