SOLVED!
The issue that i was having was that it seems like the scaleType that i had selected which 'time' seemd the right choice was not. After switching it to 'point' it solved my issue.
scaleType: 'time'
-> scaleType: 'point'
There are more types in the MUI documentation, so if it still not working try out more of them. https://mui.com/x/api/charts/spark-line-chart/