Hi there, @Epreston1 ...
In checking the "Known Issues" area of the Canvas Community website, I found the following:
[OPEN] Students with more than 50 completed items in the past two weeks show 'Nothing for now' in To...
(I found this page by going to the "Explore" menu at the top of any page here in the Community and then selecting the "Known Issues" link in the middle column.)
Last week there was also an issue with the To-Do list and the mobile app, but I believe that has now been resolved:
[iOS] Student | To-do list is showing items up until year 4001
I hope this information will be of some help to you. Sing out if you have any other questions about this...thanks!