Sitecore Publishing Service (SPS) 2.2 Update-1 - 4.0 might not republish an updated field if only the letter case of the field value is changed. For example, if a user changes the Title field value in the Home item from:
Sitecore Experience Platformto
Sitecore Experience PlatforM
the Home item is not updated.
SPS uses SQL to compare the new field data with the data that is stored in the target database. Because by default database collation is set to be case insensitive, the SQL server performs the case-insensitive comparison.
To resolve the issue, consider one of the following options: