The VBA compatibility Range.Formula and Range.FormulaR1C1 properties wrongly use localized formula expressions as if they were Range.FormulaLocal and Range.FormulaR1C1Local.
Instead, they should use English formula expressions and separators, and additionally Range.FormulaLocal and Range.FormulaR1C1Local be implemented.
For an example see discussion in bug 128334 comment https://bugs.documentfoundation.org/show_bug.cgi?id=128334#c9 and following, and attachment there https://bugs.documentfoundation.org/attachment.cgi?id=170966
Additional pointers to MS documentation in https://stackoverflow.com/a/35724386
For completeness, the endpoints are
Eike Rathke committed a patch related to this issue.
It has been pushed to "master":
[API-CHANGE] tdf#141543 VBA Range.Formula Range.FormulaR1C1 non-localized
It will be available in 7.2.0.
The patch should be included in the daily builds available at
https://dev-builds.libreoffice.org/daily/ in the next 24-48 hours. More
information about daily builds can be found at:
Affected users are encouraged to test the fix and report feedback.