Hi,
Is your code based on MQX?
If there are two or more master ,one master loses arbitration if it transmits logic level 1 while another master
transmits logic level 0. beacause the one check send data is not logic level 1 as I2C bus "and" logic.
So, if your LOSS of Arbiration bit is always set, please check if there two master working.
The BUSY bit is set, show that, your master have sent i2c START signal , but not sent STOP signal yet. please check the RXAK of I2Cx_S.