The first thing to check is that you haven't accidentally put the contacts into your phone's call blocking feature and that the contacts themselves haven't added you inadvertently to their call blocking feature @lacey
As a process of elimination can you try your sim card in another phone and then ring them.
Current Phone ~
Samsung Note 20 Ultra 5G SM-N9860_256Gb SnapDragon 865+
Samsung One Ui 2.5/ Android 10.
