Jetson can not work with PCIe bus....

We try to connect the Jetson (TX1 and TX2) with a PCIe extender bus to our PCIe device and found out it seems not to understand the TS1 (ordersets) it gets.
We connected LeCroy and the same behavior had happened… (we see other side move to TS2 and Jetson remained in TS1 until it asserts PERST# again)

We could work with the Jetson only when there was an EP or a PCIe SWITCH connected directly to the PCIe socket.

My question - why is it? Do we do something wrong?
missing some kind of power?
Is it a known issue with the Jetson? signal integrity?
Did anyone tested Jetson with a more remote PCIe devices, not connected directly to the Jetson? with LeCroy?