HWiNFO does not recognize PCI slots that are currently using bifurcation

HWiNFO reports the PCIe properties according to PCIe specification.
The controller you posted above should be representing a single NVMe drive. So it's the capabilities of one drive, not the entire NVMe card which is most likely "transparent" to "software point of view".
How many NVMe drives do you have on the card?
Then you should see 4 NVMe controllers under the respective PCIe ports/bridges. It's not obvious from the above picture though.