Side by side comparaison with red square showing what’s missing?
MC-304375
The leather horse armor texture is missing some pixels from the Bedrock Edition texture
Open
5
(Unassigned)
1524489
Confirmed
Expansion A
(Unassigned)
1.21.11 Pre-Release 1, 1.21.11 Pre-Release 3, 1.21.11 Pre-Release 4, 1.21.11 Pre-Release 5
Retrieved
These missing pixels are likely what creates this hole ingame, a leftover from the previous leather horse armor iteration as it had a hole in the same spot