I think the AC Milan precedent is worth looking at.
UEFA imposed a 2 year ban last summer after Milan were found guilty for breaches of FFP in 2015 and 2017. They appealed to CAS and were able to participate in European football. At the same time, CAS ordered UEFA to find an alternative punishment. In December, UEFA revised the original 2 year ban, and gave Milan until June 2021 to comply with their ‘rules’ or face a one year ban. Milan then appealed this decision to CAS.
Now UEFA have referred Milan to the ‘chamber’ over breaches in 2016 and 2018. A decision on these alleged breaches is yet to be announced. I would imagine if Milan are found guilty they will go back to CAS again.
As you can see, these matters can drag on and on. Unfortunately, this may well be the path facing City.