What is the distance between the lesson area, your device and your Internet signal? If you are across the house from your router, the connection speed will likely be rocky, regardless of your speed. Perhaps try to experiment with the location of your laptop/tablet or with the location of your router. Small changes in either could make more of a difference than you think.
What else can interfere with your signal? How about a microwave that uses the same frequency or an electrical panel that is nearby. Plus, a less recent model device and/or older technology cannot be ignored.