The problem seems to be this sexp from the OP's post:

(setq
 holiday-local-holidays nil
 calendar-christian-all-holidays-flag t
 calendar-holidays (list
                    japanese-holidays
                    polish-holidays
                    english-holidays
                    ;; holiday-local-holidays
                    general-holidays
                    holiday-christian-holidays
                    holiday-solar-holidays)
 ;; calendar-mark-holidays-flag t
 calendar-week-start-day 1
 calendar-date-style 'european)

Using `list' results in an unsuitable list structure.  I replaced it by
`append' (again omitting japanese-holidays), restarted Emacs, did `M-x
calendar', typed `h' on March 10 in the Calendar buffer, and the echo
area displayed this message:

Wednesday, 10 March 2021:  Dzień Mężczyzn

So I guess that should fix the OP's problem.

Steve