Combobox auto closes suggestmenu on firefox for android

Hi all,

I have a combobox that contains a few Items that the user can choose. It works fine if the showed suggestmenu is open under the combobx. But if it is on the bottom of the screen and therefore needs to be draw above the combobox it displays and automaticaly hides again.

I only have this sometimes on Firefox Desktop but almost always on Firefox for Android.
This only happens on Firefox other browsers like Chrome are fine.
Anyone an Idea on what the reason could be?