Milk Buckets Emptying/Replaced with empty buckets

After milking a cow at least once, I go to store the buckets of milk in a chest

What I expected to happen was...:
The buckets would be placed within the chest.

What actually happened was...:
The milk buckets empty and I get empty buckets equivalent to the number of milk buckets I had.

Steps to Reproduce:
1. Milk cow with bucket(s)
2. Open any chest

*Note: I've only been able to reproduce this sporadically and not very often. At the time of reporting this, I've reproduced it three (3) different times.