Before restoring the backup, you will want to print a report that shows all the transactions you have entered since the problem occurred, in case you need to re-enter them.
Go to Reports > Banking transactions. Set the Date range to Custom and set the starting date to 3/4/2022. Choose Subtotal by Account. Click the Customize gear at the top right of the report and check the Show splits box. Under Show Columns, you can un-check the Tax item box to make the report narrower. Click OK to display the report. Adjust the column widths if necessary, then print the report.
Then you should back up your current data file in case you want to return to it and restore a backup from before you installed R39.17. This would be about March 4. Verify that the problem is no longer present in the restored backup.
If the problem is still present in the restored backup, you have a different problem. You should return to your newer file and investigate further.
If the problem is not present in the restored backup, you will have to keep the backup and re-enter any transactions you entered since then.
Accept Reminders as you normally would. Be careful when accepting Bill Pay reminders to avoid double payments. Then you can download transactions and accept them as you normally would. Compare the transactions in your registers to those in the report you printed earlier and enter anything that is missing.