You cannot lexicographically compare Dates and expect that you will get the same results if you would compare real dates. For example 21.Oct.2020 < 24.Apr.2020 will return true, as 21 is lexicographically smaller then 24.
For your example “21.Oct.2020 < 24.Nov.2020” returns true for me in Mx 8.12.3, which is correct.
But why storing a date as string and then trying to compare is mathematical?