I have a strange problem that my drive door opens as if is unlocked when the door is locked with the key or with the button. The other locks do respond by locking when the door is locked or unlocked. Any suggestions?

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1990 190E 2.6
1996 Grand Voyager 3.3
1985 Mustang GT 5.0 5 SPD
1982 Suzuki GS 750T