There is a bug in the game where the raid sometimes won't end 

the raid bar will be empty but still mark 1 raider remaining 
not sure if the reason is because the last raider was not a player kill (creeper blew it up) but it caused the raid to not end, was sure there were no more raiders present because i used commands to check surrounding mobs

 THIS affects 1.15.2 but i am unable to select 1.15.2 in version selection