Minecart behavior broken when other minecarts are nearby

The bug

When a minecart is under a slope, the behavior gets altered when other minecarts are nearby, even without touching the minecart. This breaks many rail setups where minecarts go up a slope under a block.
My speculation is that either the accuracy of minecarts decreases when other minecarts are nearby, or the game miscalculates the minecarts hitbox, thinking the minecarts are touching.

Steps to reproduce

Setup 1

1. Open world “Broken Minecart Mechanics.mcworld”

2. Place a minecart on the track

   1. Place another minecart on the rail above the red concrete block (either one)

3. Press the button to launch the minecart

4. Observe the minecart

5. Repeat the process but instead of putting the minecart above the red concrete block in step 2a, place one on the green concrete block (either one)

Setup 2

1. Open world “Broken Minecart Mechanics.mcworld”

2. Place a minecart next to the sign “Setup 2”

3. Place another minecart next to the sign “Setup 2”

4. Press the button to launch the minecarts

5. Observe the minecarts

Expected results

The minecarts go uphill normally, even if another minecart is nearby the other minecarts. In all cases (setup 1 and setup 2, and regardless of the other minecarts position)

Observed results

Setup 1

• If another minecart is above the red concrete, the minecart gets stuck in the block (Unexpected)

• If another minecart is above the green concrete, the minecart does not get stuck in the block (Expected)

Setup 2

• Both minecarts get stuck, even though they don’t accelerate each other.

Media

The steps to reproduce may be a bit strange to understand, so please watch the videos to see the setups being reproduced. See ‘Broken Minecarts Setup 1’ and ‘Broken Minecarts Setup 2’.