Anyone having issues with Base defense guns?

Hi all,

Just wondering if anyone else is having similar issues to this....

I made the Titan midsection my base of operations. I placed 2 cannon turrets and about 6 sentry turrets on the mid section, they are set up to fire against everything except prey. None of the turrets or sentry units fire automatically at all. In previous versions, 1.5 or 1.6 I think, they were working. Any ideas?