How to stop fields from resetting when fail to submit form

Hi, currently I use a multiselect option, conditional-formatted to have some checkbox options appear when some multiselect options are chosen. When the form is submitted but some fields are incorrect, the checkboxes that were previously ticked becomes unticked, and the user that is registering needs to retick all the fields. Is there a way/html/css code to stop the fields from resetting when forms fail to submit?