Why are you unable to successfully Replace Item on the Maintain Par Location page when the items hav

I would like to utilize the Replace Item functionality on the Maintain Par Locations page to replace a stock item that is currently in the par location with a stockless item. However, the system returns an error due to the items having different replenishment options. Why am I able to select a different Par Replenishment Option if I am actually unable to do so? This is perplexing as the Par Replenishment Option selections are grayed out and unavailable with other Actions such as Change Item Attributes.

Thank you in advance for the help!