The LTI series tool is supposed to show recordings from a specific series, which the docs stating "To show all videos for a single series, use tool=ltitools/series/index.html;series=SERIESID", however it can end up showing recordings from other series.
This is because the series tool makes a /search/episode.xml API call using the free-text (`q`) query parameter, when it should be using `sid`:
If an event `A` exists and is part of a series with id `XYZ` and `XYZ` appears in free-text searchable metadata relating to event `B` (which is part of another series). Then event `B` will appear in the LTI series tool when specifying the series of XYZ for the series.
This should be a minor change to use `sid=` instead of `q=` when making the API call, however this may break existing integrations if institutions are relying on this bug and using the free-text query to show events for a specific series.
This has been fixed in develop (soon to be Opencast 6) so any institutions that are relying on this behaviour will have a problem when upgrading in future.