Not able to load code to Arduino Uno board

[wesleywpychowski]

I am using the app with my students (in Belgium). All worked fine untill now. The students (and me) cannot compile the code to the Arduino Uno. With the same devices, it works with the official Arduino IDE.

I cannot change the server location to troubleshoot.
Connection to another network (like my cellphone hotspot) does nog solve the issue.
The problem occurs with all of the Chromebooks and Windows laptops. Sometimes a student can load the code to the Arduino, but this is sporadic.

Is there any known issue?