This bug works a bit different for towers and vehicles. By towers I mean bunkers and bulding which can have weapon on it. All manualy controlled.

Vehicles: Select vehicles and then deselect them by pressing shift+left click (it must be single click not drag) on unit but not on interface. This will result in deselected vehicle but person controlling it will be still selected and so I can still controll it. But if you deselect like that all vehicles it will result in having drivers selcted but not beeing able to controll them interace will be blank like there is noone selected. Deselecting on interface works fine.

Towers: With towers it works like with vehicles with one exception it also don't work by deselecting on interface. While deselecting leave at least one building selected and if you order peoples inside to go somewhere all of them will get out of building. Deselecting all bunkers or towers will result in not beeing able to controll them like with vehicles. Also deselect with single shift+left click.