COUNTIFS not working as supposed


I am using the following formula to count the occurrence of any combination of String1 and String2:


The formula doesn’t correctly calculate the occurrences of String1 though. The String1 is "Abgeschlossen (ohne Erfolg)"

Using the same formula in Excel works.

I’ve uploaded a sample file here:

Look at line 68. In column D it should say 1.

Excel correctly represents this.

Thank you

simplified to:

=COUNTIF(B51:C51;"Nicht abgeschlossen|Abgeschlossen \(ohne Erfolg\)")

enable →Extras→Optionen→Calc→Berechnen→Reguläre Ausdrücke erlauben

Thank you for your answer! This works perfectly in Calc now. Do you maybe now a solution to make it compatible with Excel? Excel doesn’t correctly evaluate the regex formula.