Excel issue

I'm using Office 365, have my spreadsheets on OneDrive. I keep hitting on this issue where all of a sudden, when working on a spreadsheet, freeze panes will be grayed out. Usually, I can save my file, reopen it, and freeze panes is available again.

I do not use page layout view nor do I have any cells protected. 

Today, I am working on a very small, one worksheet workbook and I just cleared what I had frozen. Then after a bit, I decided to go ahead and freeze at row 5 (before I had frozen at a column and a row). Well, freeze panes is grayed out! I saved my file and reopened it and it is still grayed out.

See screen shot below (I created a custom ribbon). I am so tired of dealing with this issue - it's ridiculous.