Had something strange happen today while using Android Viking Clan app for server 1 I collected a completed raid reward from a raid I had joined and then clicked on the ally boss tab. Normally this only shows bosses and raid already joined There was a raid there from the same person. I said to myself - strange I just collected this so I clicked on it to confirm. Turned out to be a new raid I checked my messages and no invite. I joined of course but I can see situation where this would be unwanted Thought devs should know
Thanks for letting us know; I've checked with the developers and this can happen in some circumstances. You shouldn't be able to actually join it unless it is public, but we'll look at getting this fixed up.