Have been using 8.6.0 on a 32G FAT32 boot stick since forever.
Seamless. Perfect every time. No glitches.
The stick has one partition showing as /dev/sda1. (The host HD is /dev/nvme0n1..)
There is no additional partition /dev/sda[234].
Just lately red script caught my eye during the boot process.
The message vanishes so rapidly I had to video the boot process to catch it.

Knoppix 8.6 found at /dev/sda1
>>> Starting lin Live-Mode
>>> Please do not remove medium until shutdown!
But this is NEW:
Using /dev/sda3 (rw) [in yellow]
mount: mounting /dev/sda3 on /KNOPPIX-DATA failed: No such device
sb: Used: bad number
Overlay /KNOPPIX-DATA: partition s too small (<400M) [in shocking red]

Can anybody explain this? I repeat: there is no sda3 (or 2 ; or 4).
It looks as though mounting sda3 is part of some hardwired boot script fragment, but this has not occurred before.
Or confirm my only theory so far: the stick is on its way out and notwithstanding a clean report from all of
fdisk -l
dosfsck -r
chkdsk /f [in Windows]
it should be replaced.

But it would ne nice to KNOW, not merely GUESS.

Thank you!