u/Boring-Laugh7995

My deck in the red circled areas on this and sunfish, flex maybe a few mm at most when I stand on it, feels like standing on the hood of a truck. When I around the cleat, I heard an initial crackle and heard a little noise but nothing followed. When I push down on the cleat with all my strength it will flex about 3-4 mm. Is this normal and is this deck still solid, or is this unsafe? Sign of age? Delamination? All the other areas have no movement and feel very incredibly sturdy.