The ordinal indicators (1st, 2nd, ...) and names (First, Second, ...) are not properly displayed in Writer text set to Russian. In the case of names, a number (1, 2, ...) is displayed. In case of indicators, a dot is displayed after the number (thus, having "Separator After: ." by default, two dots are shown).
I suppose it might be the same problem as in bug 117584, where the preview might want to display the numbering localized to the LO locale, but still I file it separately just in case.
Tested with: Version: 18.104.22.168.alpha1+ (x64)
Build ID: 23c5125148a8110d88385b29570bf0b7d4400458
CPU threads: 12; OS: Windows 10.0; UI render: default;
Locale: ru-RU (ru_RU); Calc: CL
Both this and bug 117584 are the same issue (missing locale data in libnumbertext) - which is handled by pull request https://github.com/Numbertext/libnumbertext/pull/10.