Ubuntu Studio never boot on first go

[o5tu]

Hello, I use windows on one HDD and ubuntu Studio on PCIe M.2 SSD.
In BIOS there is setting to boot prior ubuntu boot but,
Ubuntu Studio never boot on first go. It loads to first screen with BIOS/Ubuntu logo, then it goes to black screen and get stack.
Than I have to restart PC and if I’m lucky, it starts on second attend but sometimes I have to restart (button Restart) few times.
Any help please.

Thank you

Operating System: Ubuntu Studio 24.04
KDE Plasma Version: 5.27.12
KDE Frameworks Version: 5.115.0
Qt Version: 5.15.13
Kernel Version: 6.8.0-52-lowlatency (64-bit)
Graphics Platform: X11
Processors: 16 × AMD Ryzen 7 1700X Eight-Core Processor
Memory: 15.6 GiB of RAM
Graphics Processor: NVIDIA GeForce GTX 1070 Ti/PCIe/SSE2
Manufacturer: Gigabyte Technology Co., Ltd.
Product Name: AX370-Gaming 5

[tea-for-one]

Are both Windows and Ubuntu Studio installed in UEFI mode with GPT?
Does each disk have an ESP (Efi System Partition)?

[o5tu]

Yes. And if I boot to Windows first and then on welcome screen, before entering the code I restart the PC, it automatically boot to ubuntu without any issue.

[tea-for-one]

As you have confirmed that each disk has an ESP, how about trying a little experiment?

Power off the PC
Isolate, de-activate or physically remove the Windows disk
Power on and access UEFI set up
Double check that your UEFI firmware is set to UEFI boot mode only
Boot the Ubuntu disk

What happens?

[o5tu]

To be honest, I’m not really in to manual disconnection of SSD. Basically it is lots of work as there is not an easy access to my PC.
When I decided to go for ubuntu I removed the PC, disconnected SSD with Windows, installed Ubuntu on different SSD.
Ubuntu was working great so I connected Windows SSD and both were working “happy together”. I Placed the PC back in place and I was able to boot to any of two systems… until one day when ubuntu started to refuse boot on the first go. I think it could be one of updates what caused the issue.
Now it looks like when is booting, it is waiting for something and if that doesn’t start (maybe X11) in time, whole boot fails.
If I’ll give ubuntu time by booting windows first (using F12 and boot to Windows) and before I log in to windows I restart the PC, there is no issue with booting.

[o5tu]

I have to add.
In the beginning of the issue I thought it could be my BIOS, so I updated that. It was working correctly accept the fact, I could see GRUB choices on every start up, which was very annoying, so I modified GRUB:

GRUB_DEFAULT=0
GRUB_TIMEOUT_STYLE=hidden
GRUB_TIMEOUT=0.1
GRUB_HIDDEN_TIMEOUT=0.1
GRUB_HIDDEN_TIMEOUT_QUIET=true
GRUB_DISTRIBUTOR=( . /etc/os-release; echo ${NAME:-Ubuntu} ) 2>/dev/null || echo Ubuntu
GRUB_CMDLINE_LINUX_DEFAULT=“quiet splash”
GRUB_CMDLINE_LINUX=“”
GRUB_DISABLE_OS_PROBER=false

(Don’t ask about 0.1, but only that was working for me)
Everything was working, so - happy days, but after a few updates is all the same.