Pcie x16 slot into multiple x4 slots

Yes, a x1 card should work in a x16 slot It's good that you've got it to work in a x1 slot What else have you tried it in besides the x16 slot

slots This enables it to clear the top PCIe x16 slot on most current motherboards

pciex16 slot configuration Well-known member looking at your image the GPU is not even fully into the slot at all its sat with all the PCI-E Card Edge out the slot

42 slot Notice that the PCIe x16 slot has a retention lever Figure PCIe adapter removal Figure Motherboard with PCIe and PCI slots Tech Tip