75% misses for memcached bucket after rebalancing

Reproduced on ubuntu 55th build
Expected misses - 50%
Steps:
According to BAT
1- Create test2memcached bucket.
2- Use 10K items with values total size equal 500M (value size is 50K)
mc-loader <host>:11211 keyset_10 valuesize 51200 sasl test2memcached
get 10K items from test2memcached bucket, get 50% misses
mc-loader <host>:11211 keyset_10 check valuesize 51200 sasl test2memcached
3-Add one more node.
4-get 10K items from test2memcached bucket, get 50% misses
mc-loader <host>:11211 keyset_10 check valuesize 51200 sasl test2memcached
5- rebalance
6- get 10K items from test2memcached bucket, expect 50% misses
mc-loader <host>:11211 keyset_10 check valuesize 51200 sasl test2memcached
Here you get 75% instead of 50%