Depending on the part of world. Problems and challenges varies. Some of these include access to technology devices, access to quality Internet connection and state of mind that can receive knowledge and information.
In Indonesia is the Internet problem, some of the remote areas do not have access to the Internet. Students need to go to the Meetinghouse to get access to the Internet.
If you were asking for the problems that may possibly arise during the maximization of technology in teaching this time of pandemic, I think it would be the students' access to gadgets and internet connectivity. It's a sad reality that not all students have the luxury of having the means to online learning.