TNT blocks that are ignited at high coordinates create a TNT entity with an offset. Depending on the parity of the coordinates the TNT entity spawns approximately half a block to the right or half a block to the left of the original location.
How to reproduce
Teleport to high coordinates (in certain cases this may lead to MC-92916)
/teleport29999983~29999983
Place a TNT block and ignite it, for example with flint and steel → ❌ The TNT entity is created with an offset
You can also verify that this is not a visual glitch by summoning entities at the positions of the TNT entities
Affects 19w13a and 19w13b. Can I request ownership of this ticket?
The following mod includes a fix for this bug, as well as a related bug where TNT blocks ignited by other explosions also suffer from precision loss: https://minecraft.curseforge.com/projects/farlands
Affects 1.13-pre1