It seems you're comparing strings instead of numeric values, that's the root cause.
This is something new.
Check the meta data of the column as you are using double inverted comas for condition.
with correct data type it will work.
Hope this make sense to you.
Hi, @AlanoudF
The cleaning formula:
IF [AgeofVehhicle] > 9 THEN '10+' ELSEIF [AgeofVehhicle] > 1 THEN '2-9' ELSE '0-1' ENDIF
btw, your formula must remove quote around number after >= and <= .
