I wish I had better info for you, but Users have reported issues with resuming from suspend on systems with AMD GPUs, including the Radeon 540X, on Ubuntu.
I have a nVidia gpu here and suffer the same if not worse black screen of death. I don’t suspend or sleep my system, I’ll just throw it in Lock Screen, till I return.
Do you have any special setting on /etc/default/grub?
This is a common grub setting nvme.noacpi=1
if you have that you might want to try to remove it, and update-grub
and a reboot.
Also Please be sure your current on all firmware updates and Bios updates.
I have a AMD CPU/GPU, and even with no nVidia driver installed… still the Black screen from resume.
Current kernel for myself is Linux 6.14.0-15-generic
Specs:
lsmod | rg -ie 'amd'
amd_atl 69632 1
edac_mce_amd 28672 0
snd_sof_amd_acp70 16384 0
snd_sof_amd_acp63 16384 0
snd_sof_amd_vangogh 16384 0
snd_sof_amd_rembrandt 16384 0
snd_sof_amd_renoir 16384 0
snd_sof_amd_acp 65536 5 snd_sof_amd_acp70,snd_sof_amd_rembrandt,snd_sof_amd_vangogh,snd_sof_amd_acp63,snd_sof_amd_renoir
snd_sof_pci 24576 5 snd_sof_amd_acp70,snd_sof_amd_rembrandt,snd_sof_amd_vangogh,snd_sof_amd_acp63,snd_sof_amd_renoir
snd_sof_xtensa_dsp 12288 1 snd_sof_amd_acp
snd_sof 401408 2 snd_sof_amd_acp,snd_sof_pci
snd_soc_acpi_amd_match 8192 2 snd_sof_amd_acp63,snd_pci_ps
snd_amd_sdw_acpi 16384 2 snd_sof_amd_acp,snd_pci_ps
soundwire_amd 45056 2 snd_sof_amd_acp,snd_pci_ps
soundwire_generic_allocation 24576 1 soundwire_amd
soundwire_bus 126976 2 soundwire_generic_allocation,soundwire_amd
amdgpu 19763200 53
snd_soc_core 434176 2 snd_sof,soundwire_amd
kvm_amd 245760 0
kvm 1429504 1 kvm_amd
amdxcp 12288 1 amdgpu
snd_acp_config 24576 10 snd_rn_pci_acp3x,snd_sof_amd_acp70,snd_pci_acp6x,snd_pci_acp5x,snd_sof_amd_rembrandt,snd_sof_amd_vangogh,snd_sof_amd_acp63,snd_acp_pci,snd_pci_ps,snd_sof_amd_renoir
gpu_sched 61440 1 amdgpu
snd_soc_acpi 16384 3 snd_sof_amd_acp,snd_acp_config,snd_pci_ps
drm_panel_backlight_quirks 12288 1 amdgpu
drm_buddy 24576 1 amdgpu
drm_exec 12288 1 amdgpu
drm_suballoc_helper 16384 1 amdgpu
drm_display_helper 282624 1 amdgpu
snd_pcm 196608 14 snd_sof_amd_acp,snd_hda_codec_hdmi,snd_pci_acp6x,snd_hda_intel,snd_usb_audio,snd_hda_codec,snd_sof,snd_compress,snd_soc_core,snd_sof_utils,soundwire_amd,snd_hda_core,snd_pci_ps,snd_pcm_dmaengine
cec 94208 2 drm_display_helper,amdgpu
i2c_algo_bit 20480 1 amdgpu
drm_ttm_helper 16384 2 amdgpu,nvidia_drm
ccp 159744 1 kvm_amd
ttm 118784 2 amdgpu,drm_ttm_helper
video 77824 3 amdgpu,ideapad_laptop,nvidia_modeset
To save you time I have personally tried these kernel params:
Tried amdgpu.dc=0, amdgpu.reset_method=2, amdgpu.runpm=0, nomodeset, pcie_aspm=force, acpi_osi=Linux, acpi_osi=Windows kernel parameters
None of which had any effect on resume. 
The Bug Team has many reports on this issue with all kinds of suggestions, but again nothing I find as a solution.