When a fence panel starts to sway, people blame the panel. The trouble is almost always at the ground line: wood posts rot exactly where they meet the soil, and a post can look fine above ground while it’s soft at the base. Push each post. If the movement is at ground level, scratch at the base with a screwdriver — crumbling, damp wood confirms it.
One rotted post means replacing that post (a new post set in gravel or concrete, panel reattached). A post that’s sound but loose in a washed-out hole may just need the hole re-packed or a concrete collar.
Also check the fixings between panel and post — screws rusted through let a good panel flap in the wind, and that’s a ten-minute fix rather than a rebuild.
Panels, posts, and gates are everyday carpentry for CMG Bridge: $125 covers the first hour, Staten Island only, Monday to Saturday.