Hi there,
You can use this custom CSS code to fix the checkbox issue.
.everest-forms .evf-field-container .evf-frontend-row .evf-frontend-grid .evf-field ul li input[type=checkbox], .everest-forms .evf-field-container .evf-frontend-row .evf-frontend-grid .evf-field ul li input[type=radio] {
margin-top: 6px !important;
margin-right: 8px !important;
width: auto !important;
}
.everest-forms .evf-field-container .evf-frontend-row .evf-frontend-grid .evf-field ul li input[type=checkbox] {
-webkit-appearance: checkbox !important;
-moz-appearance: checkbox !important;
appearance: checkbox !important;
}
.everest-forms .evf-field-container .evf-frontend-row .evf-frontend-grid .evf-field ul li input[type=radio] {
-webkit-appearance: radio !important;
-moz-appearance: radio !important;
appearance: radio !important;
}
Paste this code in the additional CSS box. You can find the additional CSS box in your theme customization option. Click on Appearance > Customize and then scroll a bit and you will see Additional CSS box. Paste this code there and it will do the trick.
Let me know if you have any other questions and I will get back to you.
Regards!