Apparently the issue is my USB analyser causing USB 3.0 Termination/RxDetect issues. When using Manual configuration of the Analyzer port, termination OFF leads to USB 2.0 only and termination ON lead to USB 3.0 connection with which i am able to connect/disconnect and change computer.
Analyzer : Teledyne LeCroy Advisor T3 FW Ver 1.18, Bus Engine version 2.25. USB Protocol Analyzer 7.35 Build 2274.
Further testing does show the issue comes from connecting the host side of the Analyzer last instead of first. The user manual does recommend connecting the host side first.
Using termination manual mode lead me to another handling situation :
When forcing termination on, USB 3.0 is enable between the Analyzer and the Device (FX3). If the host side of the Analyzer is a USB 2.0 only, the FX3 goes into compliance mode : USB USB Evt : SS_COMP_ENTRY and not USB connection occurs on USB 2.0.
I have seen issue with USB 3.0 devices where SS pairs were not crossed correctly ( Micro USB 3.0 connector as a Host connector, USB 3.0 "OTG" adapter does not cross SS pairs. After all there is not such thing as 3.0 OTG cable specification ), the host controller would go into compliance mode. Out of the 6 USB 3.0 Thumb Drive I tested, only 1 would do a fallback to USB 2.0 upon detection of SS compliance state.
How I can trigger a fallback to USB 2.0 in the FX3 once I get the Compliance Entry Event ?
I tried to use CyU3PConnectState to change the connection to USB 2.0 but doing so disable USB 3.0 and Compliance Exit Event is received. I would like to have Compliance Entry => Fallback and Compliance Exit => Restore SS. Changing the connect state triggers the compliance exit event which ends creating a loop.