Maybe you could describe the issue?
Your ‘settings being borked’ doesnt mean Manjaro messed with your HOME.
For all we know it means you are using a dated and broken theme … which becomes pronounced as plasma updates itself.
But again we dont know because there isnt any information here.
In order to find a solution (or cause) then you will need to provide some sort of description and output etc.
For example … what does this mean ?
Also might as well leave this here:
[HowTo] Provide System Information