By default, the platform does not have this option. You can use the following CSS code to remove the strikethrough in LearnDash Courses.

Please follow the steps below:

1. Go to BuddyBoss > Theme Options

2. Under Custom Codes, enable CSS

3. Append the following:

.learndash-wrapper .learndash-complete .ld-item-list-item-preview .ld-item-title>span:first-child, .learndash-wrapper .ld-table-list .ld-table-list-items div.ld-table-list-item a.ld-table-list-item-preview.learndash-complete .ld-topic-title {
    text-decoration: none;
}
.bb-completed-item {
    text-decoration: none;
}

4. Save changes 

Note: Any modifications are considered as custom work already. Know more about our Support policy here: https://www.buddyboss.com/support-policy/