steps to reproduce

1. load the attached file
2. scroll to B28

result

Blue cell is a 5 cell merged cell but it's rendered as 4 cell merged.

debug info

• keep reloading the file, sometimes zss renders it correctly. Especially load the same file in 2 different zss components in the same page. Sometimes one of two will render correctly.
• resize a column's width, the merged cell becomes correctly rendered.