Hello! Following patch https://lore.kernel.org/linux-pci/20200430080625.26070-5-pali@kernel.org/ should fix this problem. It configures controller GEN speed based on speed of connected card. So for GEN1 cards is configured SPEED_GEN_1 and for GEN2 cards is configured SPEED_GEN_2.
If you still have more PCIe cards available, could you test them if they finally work with above mentioned patch series on Espressobin?