Why won't my duravent 6 in black pipe fit into the 6 in wall

DuraVent DuraPlus 6 in. x 24 in. Triple-Wall Chimney Stove Pipe

M & G DURAVENT 6DVL-KVP 6 DVL Connector Kit, No Size, Black

Why won't my duravent 6 in black pipe fit into the 6 in wall

ALLFUEL HST AllFuel 6 in. x 6 in. Single Wall 45-Degree Elbow

DuraVent DVL Stove Pipe - How to Install DVL Double Wall Stove

Is this an acceptable install? : r/woodstoving

6'' DVL Double-Wall Black Tee with Clean-Out Cap - 8655

Reviews for DuraVent 6 in. x 17 in. Triple-Wall Chimney Pipe Out

Flammable drywall if touching vent pipe? : r/hvacadvice

Wall thimble : r/woodstoving

DuraVent 6DBK-E90SS 6 Inner Diameter - Build with Ferguson

Chimney Connection/Modified Wall Thimble

DuraVent 6DP-24 6 Inner Diameter - DuraPlus Class A