Google Calendar ignoring google_calendars.yaml search term?

I have used the Google Calendar integration for quite some time now. It used to work fine. But lately, it seems the integration is ignoring the search words in google_calendars.yaml.

For example, I have this one setup:

 - device_id: koters_school
     name: Koters - school
     search: "Schooltijd"

The calendar calendar.koters_school does still show up fine. It just turns on with any event in the calendar. It’s currently on with an event with the title ‘Onesiedag’. Doesn’t contain ‘Schooltijd’ anywhere. Why is it turning on now? Is the google_calendars.yaml no longer in use?

Edit: even weirder, I have another calendar tracked with another search term. That one DOES work. Only the ones referring this calendar turn on on all events. Why?

Edit two: The calendar that doesn’t react to the search terms seems to be missing in the integration entities page too (integrations->Google calendar->entities) - although it does populate the calendar. When I change things in the calendar, they do show up too.
But the one that does react to the search terms is also missing from the entities page.