08 Tundra Tailgate lock - not unlocking?

Just bought an 08 Tundra Limited, it’s in excellent shape, locked the tailgate with my key and now it won’t turn to the left to unlock. Any suggestions on how to get this unlocked?

 

I just tried my spare key and it opened perfectly.

 

Sounds like the blade is dull. Or the ignition has been replaced and a new key introduced.
Does the ignition key open your driver door with out the fob? Does it look identical to the spare key?

 

Sounds like a bad key

 

As others said, it is most likely a bad key. I had the exact same issue on my 07-the key would unlock and lock the doors, it would lock the tailgate, but wouldn’t unlock the tailgate. I took the lock out of the tailgate and brought it to the locksmith. He confirmed that the lock itself was fine, and it just needed a new key. They were able to make a new key using my dull key by creating what they “thought” it should have looked like when new. I was quite amazed that they got it right the first time.