Custom Sort List Excel Mac 2016 >79 entries?

Question

I have a 96-well plate with columns A-H and rows 1-12. Each well is assigned an ID, such as A9 or H12, by a machine which then spits out data in an Excel format. I need to sort the data so that they are in the same order as the plate, i.e., A1-A12, B1-B12, etc. Even if I format the cells as text, regular sorting A-Z puts A10, A11, and A12 between A1 and A2. I created a custom list under Excel's preferences, but it stops at 79 entries (G7) and then doesn't sort the rest.

I sometimes have to sort the data differently, such as A1, B1, A2, B2, etc. Again, if I do this as a custom list, it only goes to G4 (79 entries) before it stops! I did a search to see if this is a limit of a custom list or if it's a bug, but I couldn't find anything. I'm on a Mac running 10.12.6, with the most recent update of Excel (16.13 (180513)).

Is there an easy way to create custom sort lists greater than 79 entries?

Thanks in advance!

Nikki

Here's screenshots of what the custom lists look like after I put all 96 rows in: They look normal... until you scroll to the bottom!

End of first sort

End of second sort