Have a problem using advanced booking calender.

check at: https://blog.seglergemeinschaft.de/mitglieder/yachtnutzung/yachtbuchung/yachtbuchung-gohren

after selecting booking time
check with BTn “Verfügbarkeiten prüfen”
select one “>Boot auswähen” Btn
filling out the form..
try to add a booking with the Button: “Jetzt anfragen”
–Nothing happens…

– I checked already deactivating all plugins on a test env.
– I checked also with the parent and not the child..
– only when i changed the theme to a other like 2021, then booking works as expected.

cedentials for the side are the same like in the other topics i opened ..
Thx for checking

Tom