I loaded a saved game when I was playing the Abbasid Dynasty. I had researched Preservation of Knowledge, which makes all techs have a 30% discount (I know, it’s awesome). You would think that it would still apply after loading a saved game, but fun fact: no. In the screenshot below you can clearly see that I had researched it, but it doesn’t apply. Another side note is that I contacted support 6 days ago, and they acknowledged that I had contacted them, but they haven’t messaged me since.
I was in single player mode against only an AI, as can be seen on the right of the screenshot.