isNumeric in Calc Basic issue

isNumeric is supposed to return true if it receives “0.1” (i.e. a string). This works well on LibreOffice 6.1.4.2 in Linux (deb) but it does not work in LibreOffice 6.1.4.2 for OSX where isNumeric(“0.1”) returns False. Can someone confirm this and can there be any remedy?