Why is my Table data invisible except when highligted?

In LibreOffice 6.1.5.2 working on Linux Mint 19.1 in one database, in one of my tables or at least the data is invisible or white font on white, since when I highlight the text I can see it. Likewise when I copy it to calc it is fine. Can anyone tell me why this is this happening?
Also I note that in viewing different tables within the same database the presentation font is different. I am not speaking about forms but viewing in table view.

Perhaps the same problem as this post - https://ask.libreoffice.org/en/question/184443/bought-new-system-reloaded-liberoffice-micros-run-but-all-documents-show-letters-in-white-this-is-saved-and-new-docs-i-can-access-files-but-cant-read/