Portals don't refresh the countdown to unload chunks when something goes through

In all 1.14 subversions, you can send items back and forth between two linked portals to maintain chunks around both portals being constantly loaded without a player around.

In 19w36a, every 15 seconds there is a chance that one (or even both) portal will be unloaded even if it received an item a second ago.

It seems like when an entity goes through a portal, it doesn't refresh portal's countdown to be unloaded.

Portal, dropper and observers are inside a single chunk on both sides. Bug confirmed by another person.