Mac mission control add new space + icon is on left - not the right How can I fix this?

I don't recall changing a setting for this, but I really wish it was on the right as per normal (was like this prior to Big Sur update as well.)
Normal is right I assume - much better!
https://support.apple.com/en-au/HT204100
Having the dock on the right hand side causes this (unwanted) change. Hoping to find a terminal command to fix this be still unsure why Apple feels this is necessary.