Understanding Python map function + range

I'm trying to understand the difference between these lines of code:

list(''.join(map(lambda x: str(x * 3), range(1, 4))))

Out: ['3', '6', '9'] as expected.

However:

list(''.join(map(lambda x: str(x * 5), range(1, 4))))

outputs ['5', '1', '0', '1', '5'], while I expected: ['5','10','15']

In the same way that

[x for x in map(lambda x: str(x * 5), range(1, 4))]

ouputs ['5','10','15'].

What's wrong here?