Worksheet continues to freeze and say NOT RESPONDING

Could someone please help, my workbook functions normally but one worksheet keeps getting hung up. Anytime I switch cells it says NOT RESPONDING or it just freezes for a few moments. The "AG ORDERS" spreadsheet is the problematic one and it is also the most important spreadsheet.

Well, clearing the conditional formats from the sheet stopped the lag completely. So that might be one clue as to what's causing the issue.
The VBA code in the worksheet is also doing an application calculate every time a cell is changed.

The same VBA code is on the Student worksheet and there doesn't seem to be a lag on the sheet.

Sorry, that was more of an aside regarding the VBA. Your issue seems to be related to the Conditional Formats on the sheet I would say.