ok it was the problem with Bootstrap 4 CSS:
The solution is adding these lines:
$navbar-dark-toggler-icon-bg: none;
$navbar-light-toggler-icon-bg: none;
to:
resources/assets/styles/common/_variables.scss
ok it was the problem with Bootstrap 4 CSS:
The solution is adding these lines:
$navbar-dark-toggler-icon-bg: none;
$navbar-light-toggler-icon-bg: none;
to:
resources/assets/styles/common/_variables.scss