Hoteller Theme Booking Calender in 3 Languages is not opening

Hello everyone. I created a website using the “Hoteller Themeforest” theme. This also includes a booking calendar, where you can see which days are still available.
However, this website is in 3 languages. I translated this website with WPML and since then I can only open the German calendar (first language). I had this problem before and got it solved. But that was a long time ago. Unfortunately, I cannot view the history of the support ticket because the support period is only 6 months. All tickets have been deleted. I faintly remember that the shortcode [mphb_availability_???] was also translated and since then the calendar can’t be found in the other languages… But I can’t find this relevant code.

Thank you all in advance for your support. <3

Have you tried contacting the author?