Khan Academy content is not loading for a few students, but is working for most

I have been using Khan Academy for extra support this entire school year (thank you for all your hard work. It is a favorite tool for both myself, my students, and parents).  I have had great success with this program for most of this year, but recent am having 2-3 students per class have problems with content not loading (ever). We have tried connecting to different internets, tried it at home and at school.  The only thing that has been rumored to help is having students access on their cell phones. Is there anything else I can be doing to help support them?

Thanks for any and all help you can give.