I’ve always been of the perception that courts are out to get the fathers in situation like these. We hear story after story of the father being the one having to carry the maintenance.
My interactions and those I know around me have had a fairly fair outcome. I used to pay for pretty much everything but with Covid I had a significant financial knock and simply could not.
The ex on the other hand had moved to a much higher paying job than she previously had and actually earned more than me.
She refused to change anything so we went to the courts, we ended up adjusting the agreements so that I paid less and she had to carry costs now. It went in my favour as I had shown a good track record of paying when I was in a decent situation and I was reasonable as to what I could do at the time.
She was not reasonable in any situation.
Others I know have had similar situations where it was not really bias either way. The only difference really was expenses and where the kid lives most of the time (in my case it was 50/50)