> Regarding historic texts, the only thing that comes to mind is the case of Teuta in Polybius who still is referred to with the masculine title of Basileus (βασιλεύς) .

The Egyptian ruler Hatshepsut is another example. Although often referred to today as a queen – that is, a queen regnant – she in fact used the traditional Egyptian word for king (nswt, 𓇓𓏏𓈖). There was not an independent term for "queen" in Egyptian; the title usually translated as such (ḥmt-nswt, 𓈞𓏏𓇓) literally means "wife of the king," and Hatshepsut obviously could not be her own wife.

Additionally, texts from Hatshepsut's reign use both the 3rd singular masculine suffix pronoun (=f) and 3rd singular feminine suffix pronoun (=s) to refer to Hatshepsut, with some inscriptions even switching back and forth between the two. It remains unclear how much of this was intentional and how much was scribal error.

I'll also note that some ancient languages do not distinguish between masculine and feminine but rather animate and inanimate (e.g. Sumerian and Hittite). For example, whether one translates Sumerian lugal.ani as "his king" or "her king" depends on the context – which is unfortunately not always clear, particularly with fragmentary texts.