Both cylinders have almost the same topology, and are unwrapped the same way, the distorted one has longer polygons. I tried different approaches but could only make it better by inserting a loop. Is there a better way to solve this?
This was an answer I got in polycount: Select the offending face and Ctrl+T. Once it is broken down into triangles Shift+right-click neighbouring PAIRS then Ctrl+J to join them together into a Quad. You might have a few stray triangles (which is ok), but unwrapping should then work as expected.
What does he mean by ''Ctrl+J to join them together into quads''? in the blender manual to convert tris to quads the keyboard shortcut is Alt-J, and Ctrl+J is to join objects, I'm confused.