@jyamani53:
1. The menu is working fine on our server. May be some of the plugin you’ve installed it conflicting. Please try disabling the plugins one by one and check if it resolves the issue.
2. Go to Dashboard=> Appearance=> Customize=> Additional CSS box and add the following CSS:
@media (max-width: 990px) {
#content .wrapper {
display: -webkit-box;
display: -moz-box;
display: -ms-flexbox;
display: -webkit-flex;
display: flex;
-webkit-box-orient: vertical;
-moz-box-orient: vertical;
-webkit-flex-direction: column;
-ms-flex-direction: column;
flex-direction: column;
/* optional */
-webkit-box-align: start;
-moz-box-align: start;
-ms-flex-align: start;
-webkit-align-items: flex-start;
align-items: flex-start;
}
#content .wrapper #main {
-webkit-box-ordinal-group: 2;
-moz-box-ordinal-group: 2;
-ms-flex-order: 2;
-webkit-order: 2;
order: 2;
}
#content .wrapper .sidebar-primary {
-webkit-box-ordinal-group: 1;
-moz-box-ordinal-group: 1;
-ms-flex-order: 1;
-webkit-order: 1;
order: 1;
}
#content .wrapper .sidebar-primary .widget {
width: 100%;
}
}
Regards,
Mahesh