Elementor buttons that are not inline usually occur when we subscribe to a form.
This seems to be due to the default settings of the theme we are using.
Because this doesn’t happen in all themes.

I’m using the Hestia theme, from Theme Isle.
And I experienced this.

Here is the css code that I put in the custom css column to fix it.

.elementor-button {
outline-style: none;
margin: 15px auto;
}

.elementor-field {
margin: 15px auto;
}

It should be noted, that you can change the pixel number according to your theme.
Because the settings for each theme are also different.

If you experience problems, don’t hesitate to comment below.

See an example of an aligned elementor form that I managed to fix on my main web page.
hajarsabrani.com

Good luck!