Strange actions of the a tag in wordpress, why does it behave like this?

Question

WordPress

Through this code I add a link (ACF plugin)

<a href="<?php the_field('instagram', 'option'); ?>" target="_blank" class="ico-social"><i class="fab fa-instagram"></i></a>

But where he throws me (supposedly on the inside page). Something stupid, why is that?

Answer 1

because you have acf now giving:
but it should give:
Either at the beginning of the link (before the output of acf) put a double slash like this:
It's not about WordPress.