I think I have the solution, found on redddit --> My focus is under (Do Not Disturb). There are two sections (People) and (Apps). For both those sections under the Do not Disturb focus, make sure you select “allow notifications from”. For (People) make sure there is no contacts selected unless you want those notifications to come through for certain people. For (Apps) make sure apps like (FaceTime) (Messages) and (Phone) are not selected because you don’t want notifications coming from this app. I have an app called (Life 360) where I can also be messaged through so I make sure that app is not selected either. For (People) there is a setting that allows repeated calls to come through allow if you would like (I don’t). For (Apps) you can turn on or off Time Sensitive Notifications (I have it off I may turn it on idk).
In the (Contacts App), search the contact you wish to stop receiving calls from. Select (Edit) in the top right. Scroll down to (Ringtone) and (Text Tone) and select one at a time but the setting is under both tabs. The setting is called (Emergency Bypass) make sure it is off.
In (Settings), search (health pink heart) and scroll to (Medical ID), if you or they have themselves listed as an emergency contact that might let them come through as a call so maybe delete them there, however. I’m not sure about this one.