unfortunately, mintxfee doesn't work, started my bitcoind with -mintxfee=0.00005 after testing, got sent transaction with 0.00004094 BTC
Is it 0.00004094 BTC/transaction or 0.00004094 BTC/Kb?
If you paid 0.00004094 to get your transaction confirmed then everything is OK and your transaction size should be less than 0.8Kb