You are using the escape option incorrectly

df = (spark.read
  .format("csv")
  .option("header","true")
  .option("sep",";")
  .option("encoding","ISO-8859-1")
  .option("lineSep","\r\n")
  .option("nullValue","")
  .option("quote",'"')
  #.option("escape","") 
  .load("/FileStore/1.csv")
)

df.display()



------------------
a,b,c,d
10,"100,00",Some;String,ok
20,"200,00",null,still ok
30,"300,00",also ok,null
40,"400,00",null,null

CSV Files - Spark 3.5.0 Documentation (apache.org)