I've been noticing this issue as well lately, so here some more saves from my no districts@governors game.
T231 save: Mongolia is with 50 techs, T241 save: Mongolia is with 54 techs and stays at that number for the rest of the game, as further saves show, despite having >300 bpt.
Mods used were UI only: Custom Notifications, Better Report Screen and Concise UI.