Yuliya,
Can you pxplain how do you did "reset" on EVM? If it is local reset by running program via PCIE link, the PCIE peripheral itself is not reset at all and the PCIE link should be there forever. There is no new enumeration process and what the BAR enumerated before should be still there after local reset, and I don’t understand why host PC doesn’t have resource for BARs.
Maybe you did a warm or cold reset by pressing a button on the EVM? This is not the local reset in the topic.
Regards, Eric