Bittrex, on one my withdrawal sent me OBytes twice with an interval of few days. Anyone expirienced that?

Support looks like inadequate and refuse to accept that.

Or maybe I'm wrong somehow? These are transactions ids:

jJJasIustCnTGagYNSmw9KJzp5QuZGKZHrmdllzC3f4=
uh3gMPMLeXFzvdnx/9Wcf8ukZxTlPWzS9NwnZhH0eF8=

Same amount 15000614340, same destination address DHR3TJ647XOEYPQNU3UPKU5T4EEKGXKX, different sender (guess both are Bittrex wallets). I made only one withdrawal, I'm sure of that, and didn't make any other transactions from wallet or from other exchanges.