Broken stairs textures pattern in resource pack.

Partner Rank: 3

Verification Builds: 1.14.3, 1.15+

Regression Builds: N/A

Summary:
The stairs textures is broken

Affects currently Live Content: Yes

Impact: Makes the textures shown unprofessional. Although this may be a small and unnoticed error, it may affect the way players view or play texture pack related content. It will affect all the partners.

Repro Steps:
1. Open any resource packs
2. place the stair block and linked them at a 90-degree angle.

Observed Results:
The stairs that are turned into a 90-degree stair block will have a face with wrong textures readings.

Expected Results:
Stairs block should have the same textures pattern compare to the normal face the same type of block.

Screenshots/Videos attached: Yes

Notes: Happens to all textures.