I set up my game just as you show. USA P1 NK AI P2 Feb 2020
I will stop here and say you should have clearly numbered the screen shots in the order you wanted them interpreted. I interpreted them using the last number so...
57-10-17-26
I bought 8 attack helos and the purchase screen came back......
....just as it should
Next point is what did you have your air sorties set to in Preference ?
Mine was set to 8 as that was how many you showed in -26
After you rebooted your machine did you try the same experiment and get the same result?
I tried again by deleting some of the single helos and bought sections instead and the screen behaved normally
It's only a "bug" when it can be repeated