I have disabled some groups announcements since they are somewhat... spammy. But these settings will not apply on iOS build since they still come thru. I do not get notifications in-game, not on VRC website nor VRCX.
Steps to reproduce:
  1. Mute group announcements
  2. Send announcement on said group (can be your own group, this happens with any and all groups)
  3. iOS gets notification about it, your in-game nor website does not.
Video: