Problem: The client is experiencing style issues with checkboxes that started occurring after a recent update. Solution: We have confirmed that this issue will be resolved in the next WPML release. If you're experiencing this or any other issues with WPML, we recommend you open a new support ticket detailing the problem so that we can assist you in resolving it.
Please note that this solution might be irrelevant if it's outdated or not applicable to your case. We highly recommend checking related known issues at https://wpml.org/known-issues/, verifying the version of the permanent fix, and confirming that you have installed the latest versions of themes and plugins.
If you need further assistance, please contact us through our support forum at WPML support forum.