Raid Stops By Itself

We got to the last round of a raid and had only one raider left. Then, as we were searching for the raider, the raid bar disappeared. When we found and killed the raider there was no celebration because the raid bar had disappeared, so it never said "Raid - Victory".

 

This is a video illustrating the problem: https://youtu.be/GPGfLlO-1DU