Black screen after resuming from suspend (AMD Ryzen 4500U laptop from MSI)

I have a new MSI Modern 14 B4MW laptop with an AMD Ryzen 4500U APU.

When it boots, the touchpad doesn’t work (but a USB mouse can move the cursor if plugged in).
If I suspend the laptop and wake it up again, the touchpad works perfectly.
If I suspend it again, it freezes on resume and the screen is completely black; nothing works; it’s impossible to reach a TTY, and the only way to get out of the situation is a hard reboot.

While it’s booting it flashes an “error: invalid environment block” which I assume is from GRUB, and then another message saying amdgpu has failed to load something (can’t get a photo of it, it disappears too quickly).

To start with, is there something wrong with my /etc/default/grub file?

GRUB_CMDLINE_LINUX_DEFAULT="quiet apparmor=1 security=apparmor amd_iommu=off

# If you want to enable the save default function, uncomment the following
# line, and set GRUB_DEFAULT to saved.

# Preload both GPT and MBR modules so that they are not missed
GRUB_PRELOAD_MODULES="part_gpt part_msdos"

# Uncomment to enable booting from LUKS encrypted devices

# Uncomment to use basic console

# Uncomment to disable graphical terminal

# The resolution used on graphical terminal
# note that you can use only modes which your graphic card supports via VBE
# you can see them in real GRUB with the command 'videoinfo'

# Uncomment to allow the kernel use the same resolution used by grub

# Uncomment if you want GRUB to pass to the Linux kernel the old parameter
# format "root=/dev/xxx" instead of "root=/dev/disk/by-uuid/xxx"

# Uncomment to disable generation of recovery mode menu entries

# Uncomment and set to the desired menu colors.  Used by normal and wallpaper
# modes only.  Entries specified as foreground/background.

# Uncomment one of them for the gfx desired, a image background or a gfxtheme

# Uncomment to get a beep at GRUB start
#GRUB_INIT_TUNE="480 440 1"

Is this a fresh installation or have you been running Manjaro for a while? If it’s a fresh install, it may be an acpi error. For some reason a lot of newer AMD laptops have that. I would make sure the bios is up to date and try booting with either pci=noacpi or acpi=off. If the touch pad works then you will probably have to wait for a newer kernel update or a bios update. Also, is this a dual GPU laptop? If so, you could try booting with pcie_port_pm=force.