Good morning, @larry_howard ...
I had to do a bit of searching here in the Community to find the actual documentation on the "Start Assignment" wording on that button. There was a Feature Idea that was submitted back in November 2016 called Changing the "Submit Assignment" Button - Instructure Community (as you can see, lots of conversation about the topic), and just this past March, the wording was changed from "Submit Assignment" to "Start Assignment". You can find more information about why this was changed by visiting Canvas Deploy Notes (2021-03-31) - Instructure Community. So, while I'm not sure that I would say this is "wrong", it is intended behavior as of March 31, 2021.
All that being said, I'm not sure if there is any behind-the-scenes JavaScript code that your school's local Canvas administrator could implement that would change the wording on that button. Keep in mind, though, that if this was done, it would affect not only your courses but all other courses that your colleagues teach via Canvas at your school. And, then that wording would not match what is in the Canvas Guides here in the Community...which may confuse students who are reading those documents. This would be a conversation you'd want to have with your school's local Canvas administrator.
I know this might not be the exact answer you were hoping for, but I hope it has helped in some way to answer your question. Sing out if you have any other questions about this...thanks! Be well.
