Tetra Cell Serving

Hi mates
Anyone can suggest me as I am having a problem where a stronger RSSI cell is coming as Best RSSI Cell but is not serving on a patch. This patch is having weak coverage issue. Another site with 8 or more dB less is serving there.

Any idea I can change for some parameters. Are there any PER Neighbour relations in Tetra? DXT guys told me no such relation exists. And if I need to change any parameter it will be implemented on the whole site (hence for all the neighbours)

BR