DS90UB928Q-Q1: query for the I2C access of TI 928 from SER IC

Hi TI,

there is a issue for access to remote DES 928,

Host SoC system has SER 941 IC and we want to access remote DES 928 registers. 

even though the pattern gen. test of SER IC to DES shows fine operation, 

we can't read anything by I2C reading to remote DES 928. 

q1) one more thing, on the remote board, there are several ICs, 

MCU are connected to DES 928 using I2C switch (master or slave, default master to DES 928), 

if I2C of DES 928 is on slave (MCU master mode by switch), could I not access to DES 928 ? 

q2)  Is there any check point in this situation to access I2C ? 

Thanks