Steps to reproduce:
1. Try the external API REST endpoint for getting series /api/series
2. Use as filter the name "creator" as it is described in the documentation:
for example "creator:ilias"
You will get all available series not only those containing the filter name
You should get only those series with the specified filter name, namely those created by "ilias"
Workaround (if any):
Use instead "creator" the name "Creator"