TUSB1310A: Receiver Detection - no PHY_STATUS asserted for one clock

Using TUSB1310, for a USB3.0 device, after plugged into PC,  I find that PHY_STATUS, which should be asserted for receiver detection, doesn't go high. 

Strap/Drive signals:

1. VBUS is high

2. TX_ELEC_IDLE is 1

3. TX_LPBK is 1

4. TERMINATION is 1

5. RATE is 1

6. TXONESZEROS is 0

7. POWER_DOWN is 2'd2

8. PHY_MODE is 2'b01

9. RX_POLARITY = 0

10. TX_DE_EMPHASIS  = 2'b

11. TX_MARGIN = 3'b000

12. TX_SWING = 1'b0

13. TX_ELASTIC_BUF = 1'b0

14. OUT_EN = 1

Reset is normal. After PHY reset, PHY_STATUS got asserted and then deasserted which is as expected. TX_LPBK is asserted, but no one clock PHY_STATUS.

Observed RX_ELEC_IDLE de-asserted periodically.

Please help,

Thank you,

ET