You can always press F6 order to disable auto delegation on battles. This is not a bug but an intended choice. Thanks for reporting.
Yes I know, but it does not work. During deployment I put my units in specific places and groups and turn off auto deploy,but once the battle starts it ALWAYS automatically turns on at the start and I have to do everything all over again which is impossible because I have no aerial view once the battle starts. For example I might put my units into 4 groups, but once the battle starts it automatically splits them into 7 or 8 and they start running where the ai tells them and not where I put them. How can I disable auto deploy on battle start?