How did you export the key? If you used only --export then you only exported the public part of your key.
You are probably missing the secret part of your key which gets *only* exported with --export-secret-keys. Without the secret part of the key your key is now useless.
How did you export the key? If you used only --export then you only exported the public part of your key. secret- keys. Without the secret part of the key your key is now useless.
You are probably missing the secret part of your key which gets *only* exported with --export-