Marker not shown in FF

Hi,

thx for the great plugin.

Here

https://www.rbontour.de/sehenswuerdigkeiten-hansestadt-luebeck-1/

i’ve at his time 3 marker with a kml file. In chrome (Desktop & mobil) and in edge it works fine. But in firefox, they are not shown most of the time and I don’t know why. The console didn’t shows an error. Can you help me please? Thx 🙂

Greetings
Reinhard

The page I need help with: [log in to see the link]