Raids can become glitched on multiplayer servers and singleplayer worlds.  Raids don't recognize when illagers become unloaded and it can become impossible to finish a raid.  This also occurs from raids having ridiculously large ranges of 46000 blocks when they should be limited to the range of the village.  (most likely 64 blocks as that's the furthest a raid can spawn from its point of origin.)

The glitched state can be caused by several methods;

• If an illager exits the loaded chunks using a minecart or other methods.
• If an illager is spawned in the spawnchunks it gets added to the raid.
• If there are multiple players on a server the raid becomes "global" and any raiders spawned outside the original village gets added to the raid.  Villagers also 'sweat' within 46000 blocks as well.  This means that multiple raids can never occur for different players within that range.