Comparator signal ends prematurely if output block is placed next to powered detector rail

The issue:
Comparator signal ends prematurely if the output block is placed next to powered detector_rail. I was informed by 2No2Name on discord on his insight on the issue as quoted:

"This is caused by the update behavior of the comparator and the detector rails
Detector rails sends update to comparators every 20 ticks, the timer is aligned to the tick the rail is turned on. So the comparator is receiving an extra update faster than without the 2nd minecart."
How to reproduce:
Recreate the contraption in the attached mp4 file, copy the video or follow the instruction below

• a comparator on subtract mode is placed outwards from a detector_rail with a hopper_minecart. With a signal strength of 13 inputed on the side is powering a length of 2 redstone_dust indirectly via a solid block.

• The end of the length of redstone_dust is connected to a redstone_torch powering a slanted activator rail holding a hopper_minecart directly under the first hopper.

• Place a detector_rail directly next to the solid block which the comparator is outputting the signal supported by a glass block while making sure the detector rail isn't powering anything.

• Fill the first inventory slot of the first hopper with a 64 stackable items of any choice and the remaining slots with unstackable items.

• Exactly 20 items should flow through the bottom hopper_minecart, take the item from the bottom hopper and feel free to place it back onto the top hopper_minecart to repeat.

• Place a minecart on the empty detector_rail, take the items from the bottom hopper_minecart to the top. This time the number of items that flowed should be less or the same as before. If it is the same, replace the minecart and repeat the check