Plains Cree spellers installed, but does not show up properly in LO

[snomos]

I have installed the CRK spellers:

And the macOS system speller service show all CRK spellers just fine:

(except for the language name, but that is another story, not relevant here).

But in LO they do not show up as expected (compare with Inari Sami just a few lines below, which has the expected «A» check mark indicating the presence of a speller):

Instead the speller check mark can be found on the LO speller language entry for the language codes on the very top of the speller language selection list:

While selecting those language codes works, is it not the way it should be. The issue is already reported to libvoikko as voikko/libreoffice-voikko#5, but since nothing has happened in three years, it would be nice with fresh eyes on the issue. Whether the issue is actually in LO or in LO-voikko (or in core-voikko) I don't know, that needs to be debugged.