Hi there,
yes its Elementor’s CSS causing the problem, this:
.elementor .elementor-widget:not(.elementor-widget-text-editor) figure {
margin: 0;
}
Is overwriting this:
.wp-block-image .aligncenter {
margin-left: auto;
margin-right: auto;
}
Something they need to address. I did raise an issue with them on Git regarding the above CSS effecting WP widgets, this is the same thing:
https://github.com/elementor/elementor/issues/6403
In the meantime you can add this CSS:
.elementor .elementor-widget .wp-block-image .aligncenter {
margin-left: auto;
margin-right: auto;
}