Do not do your second code.
Explanation of db columns
sponsors-v2 = 2, number or rows in the repeater
sponsors-v2_0_organization = 310, row 1 (index 0) organization sub field value
sponsors-v2_0_linked = 0, row 1 (index 0) linked sub field value
sponsors-v2_1_organization = 86, row 2 (index 1) organization sub field value
sponsors-v2_1_linked = 0, row 2 (index 1) linked sub field value
all of these entries are managed automatically by ACF
You should be using add_row()
trying to insert values the way you are will break the repeater.
