PCA9615 Bus Idle Workaround?

[Widlar]

We have a PCA9615 in our design. 

Our I2C controller (differential) is powered separately from the target (Single ended.) 

The EN to the PCA9615 also enables and disables the controller power. 

When the controller power is disabled (and PCA disabled) mid communication with the target, the target can latch the SDA waiting for the next clock from the controller. 

When power is restored, the PCA9615 is enabled and sees the target SDA low. It will not connect the differential bus to the single ended bus because the bus is not 'idle'. However we cannot toggle the clock so we are stuck! I can see if I manually toggle the SCL on the target side, the system recovers. 

Are there any clever workaround for this?

[guoweisun]

Could you please help and share with your schematic here?