I assume you are using MATLAB R2019b for completing the Simulink Onramp. The above issue is a known issue and concerned parties may be investigating further. The main question that is not completed is in Chapter 7.1 Task 2. For a workaround I would suggest following steps.
In the last step of the task, after entering "3" in the "Value" field, you should also change "Location" to "Base Workspace" from the same interface, then click "Create." This will create the variable in MATLAB base workspace, and this will complete the task.
After this if all other tasks and survey are completed the progress should go to 100%.
Hope this helps.