If its an A and E (Dometic), the ratchet paw may be broke inside. The "RETRACT / EXTEND" lever only moves about 90 degrees. If it seems like it moves a lot more, it may be broke inside.
You will need to remove the ratchet end. Find YouTube videos on how to replace the awning fabric, These will show how to remove the end cap.
When we bought our "New-to-Us" Southwind, we noted the awning shaft was bent and thought it was broke inside (where the ratchet connects), so we had to remove the end cap. On ours, it was only bent, so we lucked out. We greased the ratchet and put it back together.
Repairs on main awning – 1999 Southwind 35S
NOTE - If someone worked on this in the past and the old drilled out rivets fell inside the tube, these could work their way up into the paw and jam it..
If you remove the end caps, make sure there are no parts laying inside the tube or jammed in the paw / ratchet assembly.