Bug: build commands get canceled if build area is blocked for too long

I am not sure what exactly cause this but looks that if you add lot of T1 engineers to assist things. Example use 100 T1 engineers to assist one T4 thing and then if you ask commander to build another thing outside of its building range it can just lost that command. Looks that it will not do that every time and it mostly does not do that if can start build it without chaining move or other build command. But if command needs movement or it goes some other reason to queue it can forgot it randomly. Some times it lost it immediately and some times you can see those green shadows and it lost commands after random time.