Several issues have been made about such bugs and fixed independent of each other (look for project = MC AND labels = plane-mirroring)

Many reports are still open, so I'm just gonna compile all remaining blocks into a single issue because there'd be too many reports otherwise.
Affected blocks:

• Every block using "cross" template model
• Almost all potted plants
• Glow lichen (only up and down faces)
• Amber resin (only up and down faces)
• Sculk vein (only up and down faces)
• Mangrove Propagule
• Fire & Soul Fire
• Pitcher crop
• Big & Small dripleaf stems
• Azalea/Flowering Azalea Bush (only the inner cross)
• Campfire/Soul Campfire (only the fire cross)
• Bamboo (only the leaves)
• thin_block template
  • All pressure plates & carpets (bottom face does not match the top face)
• template_orientable_trapdoor_open
• All non 3 non-orientable trapdoor models (can be spotted on oak_trapdoor, ig it should use the orientable template instead, honestly no idea why this template needs to exist)
  • template_trapdoor_top
  • template_trapdoor_bottom
  • template_trapdoor_open

Example screenshots

• template_orientable_trapdoor_open
  
• Mangrove propagule
  
• Cross blocks