I am having a recurring problem in every game I have played as the German as I research interceptors and of course build them, the auto upgrades work just fine until I get to turbojet interceptors. At that point all interceptors I have built until then cease upgrading and stay stuck as advanced interceptors. The auto upgrade of these works fine up to that point.
When I now build new units of turbojet interceptors these units will auto upgrade to improved turbojet interceptor.
The auto upgrade feature works perfectly on Fighter units, Ground Support units, Strategic and Tactical Bomber units. All of these auto upgrade all the way as each step is researched. Anyone else have this glitch and anyone know how to cure this.

When I now build new units of turbojet interceptors these units will auto upgrade to improved turbojet interceptor.
The auto upgrade feature works perfectly on Fighter units, Ground Support units, Strategic and Tactical Bomber units. All of these auto upgrade all the way as each step is researched. Anyone else have this glitch and anyone know how to cure this.