That's how it should be. The first variant 73's were 45° lock and 75° track after launch. From the early 2000's the RuAf has received an upgraded variant capable of 60° off bore and 75° tracking after launch. There is no different designation officially, it is still being referred to as the R-73 by both the aircraft avionics and personel. We have the first (early) variant in DCS.
A 90° variant is still in early prototype/R&D stages and is not fielded operationally as of today in any airforce.