I played WOT back in early 2012 and forward, eventually switching over to Warthunder for the more “realisitic” feeling. Either way, I have all the tanks prior to the SU-76 unlocked, as well as the modules required to research it. Is it because I’m on a new account? I can unlock the other tanks underneath the SU-76, and I have enough research points. It also will not let me research a certain gun despite the points I have.. At a loss on this one gents, feel free to call me a moron haha.