@IngerThompson ...
Although I'm glad to read that you got this resolved on your end, you shouldn't have to delete every assignment group except one just to get rid of the weighted groups in your course. The easiest way to remove weighted groups in your course is to go to your "Assignments" page in your course and then click on the three-dot kebab icon just to the right of the + Assignment button. Then, select Assignment Groups Weight. There is a checkbox that appears in a pop-up window where you can enable or disable weighted groups in your course. If weighting is already turned on...you can also edit the weight percentages by clicking on the three-dot kebab icon to the far right of the assignment group name. Then, click Edit. You will see an area to change the percentage. But, if you do not have weighted groups enabled, you will not see an area to update the percentage in a given assignment group.
This Guide gives the best option to configure all your group weights:
How do I weight the final course grade based on as... - Instructure Community (canvaslms.com)
Please let Community members know if you have any questions about this...thanks!