After an initial test using the project
posted by you, I have found the issue as you have mentioned.
When I opened the generated XLSB file into MS Excel 2007, if I change
the value in A1 or A2, the value in A3 is not re-calculated
automatically. Everything is fine with XLSX file though. I have logged an issue with an id: CELLSNET-28523. We will figure it out soon.
Please try the attached version v126.96.36.199, we have fixed the issue.
Looks like this did the trick.