MemcachedCacheApi returns an error for a success memcached result

[cupuyc]

We are using Play 2.6.18 with "com.github.mumoshu" %% "play2-memcached-play26" % "0.9.3"

And quite often logs contains rows like:
m.plugin - An error has occured while getting the value from memcached. ct=someClass. key=somekey spymemcached code: SUCCESS memcached code:OK
, where memcached seems returned normal response, but plugin returned failed result.

Please suggest what could be a reason of such behavior.