Someone in the apple community support page said to try this: Go to Settings > Apps > Calendar > Search, turn off the 2 settings there, reboot your device and turn those settings back on. Wait a few minutes for the search index to rebuild.I followed these steps and initially I didn’t see it was fixed. Tried searching again in 30 minutes and everything (search) works again.
Beide staan wel in het Engels, weet niet of dat hier van invloed is.
Mod, gooi maar een groen vinkje in de titel...