Now I've had some sleep I'll explain more.
initrd=* root=PARTUUID=* quiet splash rw are all set by default as is resume=UUID=* but it specifically is set in /etc/kernel/cmdline.d/10_resume.conf unlike the other values.
Setting root=PARTUUID=* like shown in the "fix" among some other things is bad because while UUID's should not change, they can in some scenarios. If it does change then the "99_fix.conf" setup as shown would prevent the system from updating the value as you are forcing the use of an invalid value. In this scenario you would not be able to boot.
Another issue that would break boot. UUIDs are unique identifiers, they are not valid for other systems. So if a user reading this followed along blindly they would not be able to boot.
Finally the "fix" shown is not removing duplicate parameters it is creating them. You are supposed to append to the defaults, not add them again as part of a change you wish to make.
For example if fake.fix=31337 would magically fix your issue you would do the following:
echo "fake.fix=31337" | sudo tee /etc/kernel/cmdline.d/99-some-unique-name.conf
sudo clr-boot-manager update
reboot
If you have no idea what you are doing then do not touch this stuff, do not advise others to touch it and never blindly trust that AI has any clue what it is on about.
