How to set port in microstrip BPF SMD module?

For a typical planar microstrip BPF, port settings were not a problem.

However, when trying to design this filter for SMT, it is difficult to set the port.

Attach a picture of SMD Type 50 ohm transmission line type.

Thank you for your help.

The discontinuity at the feed - including the transition from external microstrip to the short via at the moduel edge - could be relevant. I would co-design (EM simulate) the module including the PCB it is attached to, using microstrip feed on that PCB, and then reference shift the ports so that the refence plane is at the module edge. This way, you include the effect of all those transitions.