Following two items will impact the direction of the P-Trap.

• The location of inlet & outlet of the P-Trap. the settings should make the connection indicators the same with 2nd image.

• The setting of the service. It must be set as "Extract" for the drainage service.

When both above settings are correct, the behavior of the P-Trap will be correct. You could check if the P-Trap with incorrect behavior has the incorrect settings.

Hope my reply will be helpful.