* If I'm using the wrong place to ask this question, please forgive me, but this is the first time in my computer career when for a very long time I can't handle something so prosaic and I feel helpless as never before. If this is a mistake, please delete my post. Thank you!

[TLDR: I come here asking for advice. I can't change the volume with programmable mouse buttons for the device the sound is coming from. The buttons change the volume for another device. I'm trying to find a way to force this other device to be controlled by the mouse.]

1. My problem:
Recently, I've been using Roccat mouse with Roccat Swarm software, which allows you to program keys.
I have two buttons, under my thumb, which until now were used to change the volume, the upper — louder, the lower — quieter.
Due to other speaker issues, I decided to update my audio drivers and immediately after, the volume change feature stopped working for this device.
For listening I use speakers connected with one 3.5mm Jack connector to my main monitor. In the sound settings, it is marked as "27V2G5".

2. What I've done:
I have restored the mouse settings to default settings several times. I have installed previous versions of Realtek sound drivers several times. I also tried without a sound controller. No change. In the audio settings, the monitor is marked as the default device, and the option to take control of the device is also selected.

3. What I noticed:
What's most interesting — now that I have Realtek drivers installed, there is a device in the Audio settings that is called "Realtek Digital Output" and when I use the buttons on the mouse, I change the volume of this device. What I cannot do is get me back to the position where I can control the volume of the 27V25G.
The problem can therefore be reduced to the sentence that I cannot control the volume of a device that actually "gives sound" using the mouse buttons, and instead, regulates the volume of another device that does not participate in this.
When the Realtek drivers are not there, because I will uninstall it, it is then in devices, such as the "Digital S/SPD IF audio device", or sounding similar and again - its volume changes my buttons on the mouse.
When I turn off all the devices and leave only one, the monitor, I still can't change the volume in this way...
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OS: Windows 10 Home 64-bit (10.0, 19045)
BIOS: F23f
Processor: Intel(R) Core(TM) i5-6600 CPU @ 3.30GHz
Motherboard: GIGABYTE GA-Z170-Gaming K3
Graphics: NVIDIA GeForce GTX 1050 Ti (Driver Version: 31.0.15.3699, Date: 04.08.2023, Provider: NVIDIA)
Monitor: AOC 27V2Q (Monitor is connected to a graphics card using DisplayPort cable)
Mouse: ROCCAT Kone Air
Mouse Software: ROCCAT Swarm
----------------
- Monitor Sound Card: NVIDIA High Definition Audio
Monitor Audio Driver Information:
- Driver name: nvhda64v.sys
- Driver version: 1.3.40.14 (English)
- Driver Attributes: Final Retail
- WHQL Logo'd: Yes
- Date: 25.04.2023 01:00:00,
- Driver Provider: NVIDIA Corporation
----------------
- Computer sound card: Realtek® ALC1150 codec
Computer Audio Driver Information:
- Realtek Digital Output (Realtek(R) Audio) downloaded from the motherboard manufacturer's website (Gigabyte)
- Driver Name: RTKVHD64.sys
- Driver Version: 6.0.8703.1 [I also had version 6.0.9496.1 in the meantime - nothing changed.]
- Driver Attributes: Final Retail
- WHQL Logo'd: Yes
- Date: 14.05.2019, 01:00:00
- Driver Provider: Realtek Semiconductor Corp
----------------

I beg for help. I care a lot about it. I'm actually addicted to this feature, it's been with me for over a decade and I can't imagine living by having to use a physical potentiometer to change the volume.

Thank you for any comments or messages on this matter.
I assure you that I will reward you if someone helps me solve this problem.

Wish you all the best, take care!

// Dominik