I noticed that the weekend beginning July 1 was skipped when importing the May 2019 study edition, with its article (Love and Justice in the Christian Congregation) assigned to the weekend after. As a result, July 1 was empty and the weekends after were out of sync by a week.
If you encounter the same, correcting this is pretty easy:
1) Backup the Database, then close Theocbase
2) Open the Database, navigate to the 'publicmeeting' table and sort by Date descending (latest date is row 1). You will likely see something like this (notice the missing week between 2019-06-24 and 2019-07-08)
3) Change the dates working backwards, ie.
2019-08-05 becomes 2019-07-29
2019-07-29 becomes 2019-07-22
2019-07-22 becomes 2019-07-15
2019-07-15 becomes 2019-07-08
2019-07-08 becomes 2019-07-01
4) Ensure the changes are written to the database, re-open Theocbase and everything should now line up properly.
Sidenote: the 'publicmeetinghistory' table should update automatically after the changes to 'publicmeeting', but it is good to double-check this. After the changes, 'publicmeetinghistory' should look like this (mtg_date will be a day later if your weekend meeting is a Sunday):