The passuk in Devarim 3:14 says:
יָאִ֣יר בֶּן־מְנַשֶּׁ֗ה לָקַח֙ אֶת־כׇּל־חֶ֣בֶל אַרְגֹּ֔ב עַד־גְּב֥וּל הַגְּשׁוּרִ֖י וְהַמַּֽעֲכָתִ֑י וַיִּקְרָא֩ אֹתָ֨ם עַל־שְׁמ֤וֹ אֶת־הַבָּשָׁן֙ חַוֺּ֣ת יָאִ֔יר עַ֖ד הַיּ֥וֹם הַזֶּֽה׃
Jair son of Manasseh received the whole Argob district (that is, Bashan) as far as the boundary of the Geshurites and the Maacathites, and named it after himself: Havvoth-jair—as is still the case.
But it seems that this war was in the same time of the war with Og and Sihon, so just some days/months before this speech of Moshe ! So why does he say "as is still the case"/"עַ֖ד הַיּ֥וֹם הַזֶּֽה" ?
I'm also surprised that no one of the mefarshim ask this question, that seems obvious. The only one (on sefaria) is Birkat Asher, who answers that it can be a trope for "and it will remain so"; but it does not seem to be the case in the Tanah.