DataTable won't update after adding new info to source

[uggliMuggli]

Ok, I'm stuck.

Screen1: I have a form that allows an instructor to requests textbooks for an upcoming course. They select/enter the course info, that's all put into variables, the only one that really matters for this is varCrsID. It looks like 99999DEPT99901. 

Screen2: This screen has a form where you put the book information in it and click a button to add that book request to the excel file. Also contains a datatable with items = filter(table1, varCrsID in CrsId). After a new book is requested, the datatable WILL NOT update to show the new book. I mean, it was working for like, a day, but now it's not unless I refresh the app.

I also tried to do OnVisible = ClearCollect(datatablerows, Filter(table1, varCrsID in CrsId)) on screen2 as well as running a timer that lasts 5 seconds and refreshes the source on timer start and updates the collection on timer end. Datatable items = datatablerows for this. That works great.

Here's where it goes wrong. I finally got the request screen working, so I went to update screen3.

Screen3: Shows datatable2 with the same items as screen2 datatable1, as well as an edit form that allows people to modify or delete the requests based on datatable2.Selected. This worked well when datatable2 items = Filter(table1, varCrsID in CrsId), but still didn't update the datatable after the record was changed. Then I tried to change to items = datatablerows. Of course, the selected property of datatable isn't compatible with forms when datatable items is a collection.

Any tips on how to get datatable to continually update and let me use the selected property?