A loan officer is not able to select Lock Extension or some other type of Change Request, and they are seeing a yellow triangle.
Hover over the yellow triangle to view the reason the change request option is not available.
This will show you what to focus on when you look at the change request settings for the investor entity in Config.
Another place to check is the Change Request section on the 2ndary Options page of the loan in question. A secondary user may have unchecked the option needed.
CA Best Practice:
Do not assume that the customer wants to edit their settings. They may have their settings correct, and just forgot they had it set that way. In your reply to the customer, explain why the change request is not allowed and how they can go about editing their settings if they wish.