Reproduction Steps

1. Place the following blocks in the correct direction (See layout1.jpg). Command block command:

   summon tnt ~1 ~-0.5 ~ {Motion: [0d, 0d, 0.01000005d], Fuse:80}

1. Press the button, watch the summoned tnt

Expected behavior: TNT falls straight downwards. The tnt was outside of the slimeblock, so it shouldn't be affected by the moving slimeblock

Actual behavior: TNT gets launched forwards. See behavior.gif and behavior-0.2x.gif (slowmotion version)

Analyzation

Maybe due to some 1E-7 magic margin number in entity collision codes

Affected versions

Tested and reproduced in 1.14.4, 1.15.2, 1.16.5, 1.17.1, 1.18.2, 1.19, 1.19.3

Doesn't affect 1.13.2