Even though the hopper is 1 block tall (or less if we look at the middle part where entities are also able to fall) a hopper minecart cannot pick up the dropped items at the top of a disabled hopper, when the track is directly below the hopper.
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Comments 1

Thank you for your report!
We're actually already tracking this issue in MC-171781, so this ticket is being resolved and linked as a duplicate.
If you would like to add a vote or any additional information to the main ticket it would be appreciated.
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