I am using the module Magento 2 Custom Option Image v1.1.4 on Magento 2.3.4 and have the issue.
The checkbox field has not been in vertically middle, but in the top of the box.
Can you advise how to fix it?
This issue is caused due to the conflict with the 3rd-party theme Alothemes/expert1 on the site.
To fix that conflict, we would like to give you a guide as below.
Please add this file on your site and then flush the cache: app/design/frontend/Alothemes/default/Bss_Customoptionimage/web/js/image-preview-static.js
If you need any assistance, please feel free to contact us.
We are always willing to support you.