Bug in Asian language input in Calc

I can enter Tibetan text with no problem in Calc on my iMac, LibreOffice version
But on the Macbook Air, LibreOffice version it is broken: symbols that are supposed to be stacked appear separately. I can enter Tibetan text accurately and easily in other programs on the Macbook Air.

How do I report this as a bug?

May I propose to file a bug report here: https://bugs.documentfoundation.org/
Please note that for selecting the LibO version you need to scroll the Version list up