Horses and bred cows disappeared

After spending a couple of Minecraft days underground both the 2 horses I had tied up and the entirety of the cows I have bred have disappeared. They have not escaped, there was no hole in the enclosure which I did close, the 2 horses were tied up near my base, had they simply somehow escaped I would’ve been able to find them easily. I believe I’ve heard that this issue had already been reported and fixed but it seems to persist in Minecraft PE at least. Thank you in advance for reading my message!