Hello Kari, welcome to the Microsoft community, I'll be happy to help you today;
I understand that the default printing continues to be changed by Windows;
What exactly is the model and manufacturer of your printer?
After disabling the option "let Windows manage printers" you can manage your default printer manually;
Access Printers and Scanners again;
Select your printer and click on Manage;
Click Set as default;
Check if the problem has been fixed;
Hope this helps, see you soon!