Dear ans7
Thank you for choosing the Microsoft Community.
Based on your description, I know you're trying to turn client-specific rules into server-side rules. First, a rule may be a server-side rule or a client-specific rule, and the classification of the rule depends on the conditions and actions applied to the rule.
When setting a rule, after some conditions and operations are set, the corresponding rules will become client-specific rules, and the rules you create must involve relevant conditions and operations. For example, if you set a rule to permanently delete messages with specific words in the body, your rule is server-specific. You can view the specific conditions and actions involved in client-specific rules in Server-side vs. client-only rules - Microsoft Support. As a result, we can't change a specific rule that you set from a client-specific rule to a server-side rule, and if you need to change it, the conditions and actions in the rule you create will change. In this case, the rules you create are not the rules you want.
Hope this can help you. If you have any other conuslt, please feel free to let me know.
Thanks for your precious time. Have a nice day.
Sincerely,
Katherine