villagers raising prices and disappering for no reason

1. After a lot of trades with two farmers the pupmkin price raised to 15 for 1 emerald and 8 for an emerald. I have a third villagers who lowered the price to 5. I have not hit the villgers once.

2. I was afk in my fish farm for the night and when I got back to the game about 5 villagers disappered, and even loggin off and back on didn't help. the place they were at was fully lit, so was the area around it, and the entrance was blocked. It couldn't have been a zombie because I still had 2 villagers left. My sfk spot was about 3 chunks away from the villagers.

UPDATE: This just happend again!! I lost 15 villagers this time, they were even renamed with a nametag. It happened in the same chunk as the previous one, and in the chunk next to it, all of the villagers remained unharmed