This BUG can be split into multiple small issues.

First, when the chunks of the raid is not loaded before starting to check whether the raid's mobs exist, the unloaded mobs will be excluded, and the raids will end with several pillagers in village. This can be reproduced by quitting the game far from pillagers(in different chunks) and opening the save laggily. When you entered the game, the PostRaidTicks will already have some number even if the raid still exists.

Then, the TotalHealth can go insanely high, when the raid happens near a Outpost or WitchHut. The game should change the TotalHealth ONLY when the health at present maxes out.

The central coordinates(CX, CY, CZ) can go zero when I unloads the raid's chunks for a long time, and also links to MC-140181

If a player triggers a new raid when the old raid's PostRaidTick is ticking but the old data is not deleted, a new raid will IMMEDIATELY start(since the PreRaidTick is 0) , with a new ID, higher BadOmenLevel, but all the other data is directly inherited from the old data(the PostRaidTick just stops counting since the "new" is going on)