Welcome to the Forum @Dave_Friedman and thank you so much for taking time to report this.
I can’t seem to be able to reproduce this on my end. I run an advanced search for tasks assigned to me with due date within the next 5 days and then I sorted by Due Date. It worked fine on my end.
Can you please share the steps you are following to reproduce this? Can you also confirm which browser and version are you using? Would you mind to try with a different browser or incognito windows as well to see if this behaviour persists?
Thank you for your help! Looking forward to your reply!