Problem with the research of the russian

Originally posted by Papy_Jeannot: I have a problem with War Thunder. I'm currently trying to advance in the tanks of the Russian stream but I'm stuck at the SU 100P because as soon as I finish a battle and therefore receive my battle rewards, these same research rewards don't apply to the tank I'm looking for but rather to a helicopter: the MI-24A.
How do I get research rewards to apply to my tank?

When you are in tech tree, take a look at bottom right corner of it. There is a checkbox. If you mark it, you will research helicopters while playing ground vehicles.
Unmark that checkbox.