hosted application, with map polygons, work fine on Chrome and Microsoft edge, but polygons create problem rendering on Mozilla

I am creating a shiny app which renders country polygons on a map based on the selection in the input panel, and the panel also has a chart which updates based on the choice of the country on the map. You can find the working app on the following link which i have hosted on free version of shinyapps website:

Problem: The issue is that when I use Chrome and Microsoft edge to load the application using this link hosted on shinyapps website, all the polygons on the map load fine. But when i open this link on Mozilla firefox, the polygons on the map do not load/show up. However, once the base-map has come online on Firefox, if we select any radio button provided on the input panel other than the one which is pre-selected on the panel, and then again go back to the pre-selected radio button, the polygons start to show on the map, and the problem goes away.

Also, note that the application works fine on all the three browsers if you run the code locally on rstudio. The issue comes when i host it on shinyapps website and open the app using the address created by the shinyapps.

I am not able to figure out what is the problem here, and why the application link works flawlessly on chrome and edge but not on Firefox. And how to fix this.

The actual application code is large, and i have tried to reduce it but the code is still big. I wanted to provide all the minimum connected pieces for reproducibility, so, i am providing the github link where the code and the shape files can be cloned.

I am unable to figure out if my code has issues, or there is issue with shinyapps website or Mozilla has the problem.

I will really appreciate any help.

Thank you.