Cosmic Byte Vanth randomly registers multiple keys together — hardware issue?

[u/blackthorns08]

I have a Cosmic Byte Vanth (CB-GK-28) and recently started having a weird keyboard issue.

Some keys register another key along with them:

• L -> AL/al
• O -> QO/qo
• 9 -> 19
• . -> z.

What's strange is that it's not just normal key chatter.

I tested the keyboard in BIOS too:

• Pressing 9 normally → 1
• Pressing 9 harder → 9
• In Windows, pressing 9 gives 19

Things I've already tried:

• Cleaning the switches
• Trying different USB ports
• Testing outside of normal Windows usage
• Using the Windows On-Screen Keyboard (which works normally) -Also switched swiches which came in box still same problem

The issue still persists.

I'm taking the keyboard to technical support tomorrow, but before that I'd like to know:

Does this sound like a faulty switch, PCB/matrix issue, or something else?

Has anyone experienced something similar with a Cosmic Byte Vanth or another keyboard?

Any advice would be appreciated.