In 1.20.6, double doors required doors of the same type. For example, oak and iron doors placed next to each other did not form double doors. This is no longer the case in 24w21b. Likely caused by the fix for MC-266290. Possibly WAI.

Steps to Reproduce

1. Place an oak door.
2. Place an iron door next to the oak door.

Expected Result
Double door is not automatically created.

Actual Result
Double door is automatically created.