As has been alluded to in this and other posts, TVD has the look of a QB who is thinking way too hard, and that's to be expected considering where he's coming from. Only started half the season last year with a different OC - an OC with an incredibly simple and QB-friendly offense. Now he's being asked to process a field with his go-to WR out and lo and behold he's a tick slow and low.
I will say TVD is too hard a worker and too much of a competitor to fold and break, but the current offensive struggles of our "1st round QB" shouldn't be all that shocking.
And yes there are things that Gattis can do to mitigate some of this - shorter fields, more RPO, etc but personally i think the more Gattis tries to tweak things for TVD the harder it will be for him to pick up the totality of the offense long-term. Realistically (and unfortunately), the best fix is time.