Missing unit in padding for submit button in contact form widget

As per the subject.
When using Contact Form widget and styling the submit button with custom padding the generated dynamic CSS is missing unit (px).
Example: When changing padding to 25 with “px” selected as units the front end generated CSS style is:

.so-widget-sow-contact-form-default-9766b3acb4a7 .sow-contact-form .sow-submit-styled .sow-submit {
    color: #ffffff;
    background: #474747;
    border: 0 solid #989a9c;
    border-radius: 0px;
    font-weight: normal;
    padding: 25 50;
    display: inline-block;
    box-shadow: inset 0 -1px 0 rgba(255, 255, 255, 0.07000000000000001);
}