old bug was:
In vanilla, whenever I got the free ToE techs, a pop-up showed the (e.g.) metalurgy tech icon although I picked (e.g.) atomic theory. Also it said "We learned tech X from the ". It [i]should have been something like "Our scientists discovered atomic theory".
However, knowledge was updated correctly.

Now in C3C, I got philosophy as first civ on the planet, hence I could pick a free tech. Took construction, but pop-up says sth like "Sir, we have learned polyteism from the Zulu". Actually, I already knew poly for quite a while (btw, traded before from Zulus indeed) and certainly got construction for free.

Seems like a pop up failure (and as mentioned, I got similar probs in vanilla before).

Recreate:
Discover philosophy as first civ, choose new (free) tech on the tree; *possibly*(?) have ever made a tech deal w/ another civ in the game before.

Haven't built ToE yet in C3C, but I guess it'll be the same then...