How to secure privacy lattice to top of existing fence gate?

Question

I want to fix some privacy lattice installed along the fences at a property I maintain. Most of the lattice installed along the actual FENCE is solid - I’m assuming because the bottoms of the lattice can be securely anchored to the top of the fence. However the lattice that’s installed along the fence GATE itself is in extremely poor condition. These pieces are either already leaning, with the fasteners (nails) almost pulled free — or in various stages of failure, and require cosmetic and structural repair. (Pictures below)

1. Is this happening because of weather changes, the decision to use nails as fasteners on a frequently moveing object or BOTH?
2. What is the ideal way to re-secure or rebuild the privacy lattice above the gate area specifically? Obviously the gate gets opened and slammed shut hundreds of times a year and i want the repair to be able to take that abuse. Maybe a combination of strong deck screws and possibly U-brackets of some kind to fortify?

Answer 1

My first choice would be rebuilding the gate with continuous stiles from bottom to top and diagonal brace running from the rail below the lattice to the bottom. You can reuse the boards and hardware, so it won't require extensive amounts of new lumber and will match the existing fence from the outside.

It's hard to say without seeing the framed side, but I suspect any repair is going to be unsatisfactory in the long run. That lattice box is just too much mass to be unsupported. Sistering a second two by to the bottom of the lattice frame and finish nailing through the boards will prevent it from moving independently, but you're really asking for trouble if people are rough with the gate.