A Discord user named thirdchris reported an issue where after the Erosian War, attempting to talk to Riala about research immediately ends the conversation without dialogue. Conversation and save file start here:
https://discord.com/channels/896059111106551859/896275520390574101/934471561694556220
They did say they have edited their save file but only for Sx and ProN.
I took a look at the Riala event in RPGM and all of the switches checked are off:
2600 Research Available is off.
2590 Prep: Tower Delving is off.
2591 Prep: Wendis Body is off.
2592 Prep: Demonic Research is off.
3562 Research Blocked is off.
It looks like when all of these are off the convo just ends.
I'm unsure if it is possible for these switches to be off in a normal playthrough but I think this is as far as I go for right now. Someone more familiar with the game may want to take a look. From the user:
this is my first playthrough and i didn't start following the guide til like the yhillin war and i don't necessarily use it for everything so i do miss some stuff here and there but mostly managed to maintain positive results. one of the tables in the erosian war says if you got under a certain amount of points the result was "research locked" but i did not get the dialogue indicating that and somehow i can't research anyway