Optional Date fieldset errors when saving new entry

[katwlodarczyk]

Hello, Im working in Statamic 4 and have events collection.
Each entry has start_date (date fieldset), multi_day_event (toggle) and end_date (date fieldset).
If multi_day_event toggle is true then end_date field will appear, however if its false (so its a 1 day event), I can't save the entry and the error "end_date must be an array".
Obviously end_date is empty.

end_date has set

 validate:
     - sometimes
  if:
    multi_day_event: 'equals true'

I've also tried without any validation, with the same outcome.
How can I fix this so 1 day events are possible?
Thanks!

[katwlodarczyk]

https://github.com/statamic/cms/releases/tag/v4.4.0 <- this update fixed the date validation