I confirm the same issue after update to 1.7.3 and 1.5.19 on two sites using Elementor Pro form on one and WP form on the other.
Safari somewhat got the tick back after adding:
input[type=”checkbox”] {
-webkit-appearance: checkbox;
-moz-appearance: checkbox;
}
However, Chrome still shows a square in it and Mozilla has ‘fooc’…
Thanks, @momo-fr and @harrisdesigned – both hacks got it fixed!