I am playing the 1936 Europe scenario as the Americans on Chieftain difficulty (don't laugh, I'm seeing what this mod is before trying it on a harder difficulty). Before entering the war (fortnight 1 December '41) research items took 4095 beakers to complete, afterwards (fortnight 2 December '41) they are displayed as requiring 17195 beakers but are completed the turn after selecting them.

Attached is the Fortnight 1 December '41 savegame.

Spongeing off your allies eh? :p

Allies research is cumulative.

That doesn't seem to be the reason. I can get research completed in 1 turn when I am researching something different than my allies.

For example: My allies are all researching Improved Anti-Air and I am researching Chain Reaction, it will take them 20 turns to complete Improved AA and 1 turn for me to complete Chain Reaction, when I join them in researching Improved Anti-Air, it will only take 1 turn for all us to complete it.

yes, i also notice this problem too prior 3.13 patch. I was playing as Germany at noble (1st game) and when east balkan joins me, he can research any tech in 1 turn for 3 times, while I can normally do it in 6-8 turns. I'm pretty sure east balkan is not an economic powerful house. Either he did not research anything at all since the beginning of the game or this is a bug.