When something is seemingly true, it looks like it is true, but it might not be true.
Seemingly can make people think of doubt or uncertainty.
Examples:
The sky is seemingly blue, but it might not be.
She is seemingly happy, but I'm not sure.
Seemingly, the cat is sleeping in the sun.
The cake is seemingly delicious, but it might not be.
Seemingly, the mountain is very tall, but it might not be.
Seemingly, the treasure is hidden in the cave, but it might not be.