I have exactly the same annoying issue. Exaclyt the same solutinon which is to export to Pages O9
In Pages 5.2, the text shows up and prints fine when it is not in a table, eg a chemical equation such as P3 + CL → PCl3 (with the nubmers set up as subscripts.). In any table, only the first part prints and nothing else. No tinkering with any of the settings such fonts, indents, cell wrap, etc makes a difference. When exporting to PDF the same issue happens. This also happens with the external editor Math Type, ie the text is fine in a free line outside of the table, but truncates in a table.
It is relatively easy to fix this, but annoying, by exporting to Pages 09.
This is presumably a bug and I reported to Apple.