How to ensure adjusted min and adjusted max don't disappear in table

Summary:

We have over 500 items we want on for replenishment through the plan. However, they are not given a minimum or maximum. I made a Min/Max table to adjust these values from null to new value. However, the adjusted minimum and maximum disappear after a week. I want to ensure these stay adjusted forever unless changed.

Is there a way to configure this? I am using Replenishment Planning.