Iron Bars texture mapping error

Partner Rank: 3
Partner Team Reporting: Foxy
Verification Builds: v1.16.221 (current release) & Beta v1.17.0.52 (latest beta)
Regression Builds: Went back to v1.5 and bug was still present. No idea if this was ever correct.
Summary: Iron bars' texture is not mapped correctly to its block model, resulting in almost the entire left half of the texture being ignored.
Affects currently Live Content: Yes
Impact: Not game-breaking but my current project heavily uses re-textured iron bars for a certain visual effect. As custom block models do not yet support multipart models, I am not able to make a replacement block with adjusted mapping in the meantime.

Repro Steps:
Step 1: Place some iron bars.

Observed Results: The left half of the block uses a mirrored version of the right half of the texture. The left half of the texture appears to be completely ignored. Upon closer inspection it seems that the central post element of the block model is correct (EDIT: post's texture appears to be mirrored), but side elements that extend from it to adjacent blocks seem to exclusively render the right half of the iron bars texture.
Expected Results: Side elements of the model should use their respective sides of the texture.

Screenshots/Videos attached: Image comparing texture to in-game appearances in both Bedrock and Java is provided.