I encountered the same issue on my Inspiron 5485. I found that setting "Sleep Mode" to "Force S3" in the bios enabled Ubuntu 19.04 to install and run cleanly. You can find more details here, including the real debugging done by others: [URL]
I recently bought a 5585 with AMD Ryzen 7 3700U APU, and tried to install the Linux for dual boot with built-in Win 10. Created the USB Linux bootable stick and configured the BIOS to disable the secured boot/fast boot as instructions online. But every time I selected the 'install linux' or 'try linux' via UEFI mode from USB boot GNU GRUB, the laptop would then freeze and stuck with a black screen.  Also tried to set the Linux boot parameters in GRUB, e.g. 'nomodeset', 'amd_iommu=off', noapci, noapic, etc. Almost all the ways I found in community and other online forums, but still failed to install dual bootable Linux, which makes me a bit frustrated. Hope to get help and any idea to resolve the issue. Thanks
Inspiron 5585 AMD Ryzen 3700U APU Linux dual boot install issue