After getting access to this settlement's workshop all I can prompt from penny is the Trade option to go through her inventory. She no longer will dialogue with me so I can ask to barter with her. This has prevented me from trading with her as well as buying the legendary shotgun off her. Is there any way to fix this issue?

After writing this post I finally got dialogue. She seems to linger at her shop and is very finicky about when I can actually trade with her even though it looks like shes available.