Double check with the /seed command on both the realm and your world.
Depending on how you got and entered the seed one or more of the following might apply.
Your friend mistyped when they created the realm and told you what they thought they had entered.
Either the seed of the realm or the one you entered might have a space at the beginning or end which would make it a completely different seed.
Also I believe using citation marks around a seed makes it be interpreted differently.
Or, according to a few earlier threads in the forum, it seems that worlds, perhaps particularly on servers for some reason, can become corrupted in such a way that the seed changes. So even if the seed is now 69420 most or all of the world may have been created with the original seed.