Wrong flow logic regarding Airtight Pipe entry/exit

Placing a pipe on the side of Airtight Pipe entry/exit causes wierd water flow behaviour.

How to reproduce:

• Place Pump/Intake Module to the water.
• Go one node above it and place a pipe there.
• Go one node to the west and place a pipe there.
• Go one node to the west and place an Airtight Pipe entry/exit there, oriented west-east (this will connect to the tube segment).
• Go one node to the west and place a pipe there.
• Go one node to the north and place a pipe there.
• Go one node to the east and place a pipe there.
• Enable the Pump/Intake Module and wait till all pipe segments get loaded.
• Disable the Pump/Intake Module.

Expected behaviour: After disabling the pump, all pipe segments should become empty.

Observed behaviour: Pipe segments are switching between empty and loaded state periodically, probably due to error in the flow logic.

Used Minetest 5.6.1 (Minetest Game) with basic_materials, dreambuilder_hotbar, pipeworks and unified_inventory mods.

Reproduce the listed Minetest setup and placement sequence, focusing on the Airtight Pipe entry/exit and the adjacent pipe loop. Inspect the pipeworks flow logic responsible for loading and emptying connected segments after the pump is disabled. Done means all segments remain empty instead of periodically switching between empty and loaded states.