Just to confirm this is the antenna connector that is located near the battery connector near the edge of the board right?
If yes, the problem might be that the gold ring or the dot in the gold ring is bent or damaged. When that happens it does not let the antenna cable plug in and will keep popping up.
The recommended way to get this fixed is to get the connector replaced on the board. If it’s the cable connector on the antenna cable itself that is damaged then either the charging port assembly needs to be replaced or another antenna cable soldered onto there.
Might want to post some photos of it here so we have a better idea of what we are looking at:
Adding images to an existing question
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