I just installed the Tuta app from the Play store, made a test contact, and enabled its "sync to android" feature that exposes tuta contacts to the system and other apps.
- various other apps like fairemail and google contacts can see my tuta test contacts in realtime (i.e. with additions or changes)
- my Simple Contacts Pro does not show Tuta as a source to enable and does not show the contacts in a search, even after an app restart, cache clear, and phone reboot
Discussion about this issue in tuta repo (dev says it's a contacts app issue, not tuta)
Samsung s23+, android 14, belgium (english)