When things are all mixed up, especially things that are normally separated in some organized manner, they are said to be "jumbled up".
As an example: someone who just throws all their tools in a big box - those tools are then jumbled up.
Instead of using a tool box or tool bag, etc. where the tools are stored in some order and thus easily selected for use. No need to dig around looking for a specific tool.
A battery does not get mixed up or jumbled.
The actual intent may have been to suggest that the CMOS configuration settings were incorrect in some manner.
If someone went into the CMOS configuration and just randomly made changes then those would be errors.
I would not consider that to be mixed or jumbled up. But I can see how it could be viewed that way in some circumstances.
Resetting CMOS would put things back in order and, could be viewed as no longer "jumbled" up.
English can be very strange sometimes.