I don't know why this was labeled as a solution, when it doesn't solve my problem. I think it is a bug in the code because I am not the only teacher here at East Tech that has experienced this phenomenon.
I am the only person working within my Canvas courses, so unless you are suggesting that an administrator altered something and then changed it back, it is a problem in the code.
For further clarification, these are text entry assignments. And for some reason, Canvas has allowed students to access the assignment page outside of the dates/times that they should have been able to access it. I tried to chat with support but waited over 10 hours without anyone joining the chat.
Feel free to look at the images. The first assignment was already closed, and yet a student was able to submit their assignment a day after the close date. The second assignment hasn't even opened yet, and there is already a submission.