In OpenCart 3.x, a bug has recently occurred: when adding a product, category, article, manufacturer, etc., the content is duplicated. When you save, two copies are created. This problem is mainly in the Google Chrome browser. This is due to the form attribute, it does not work correctly in Google Chrome. How to solve the problem:
in products, file \admin\view\template\catalog\product_form.twig
change
<button type="submit" form="form-product" data-toggle="tooltip" title="{{ button_save }}" class="btn btn-primary"><i class="fa fa-save"></i></button>
on
<button type="button" data-toggle="tooltip" onclick="$('#form-product').submit();" title="<?php echo $button_save; ?>" class="btn btn-primary"><i class="fa fa-save"></i></button>
in categiries, file \admin\view\template\catalog\category_form.twig
change
<button type="submit" form="form-category" data-toggle="tooltip" title="{{ button_save }}" class="btn btn-primary"><i class="fa fa-save"></i></button>
on
<button type="button" data-toggle="tooltip" onclick="$('#form-category').submit();" title="<?php echo $button_save; ?>" class="btn btn-primary"><i class="fa fa-save"></i></button>
inmanufacturers file \admin\view\template\catalog\manufacturer_form.twig
change
<button type="submit" form="form-manufacturer" data-toggle="tooltip" title="{{ button_save }}" class="btn btn-primary"><i class="fa fa-save"></i></button>
on
<button type="button" data-toggle="tooltip" onclick="$('#form-manufacturer').submit();" title="<?php echo $button_save; ?>" class="btn btn-primary"><i class="fa fa-save"></i></button>
in pages (articles), file \admin\view\template\catalog\information_form.twig
change
<button type="submit" form="form-information" data-toggle="tooltip" title="{{ button_save }}" class="btn btn-primary"><i class="fa fa-save"></i></button>
on
<button type="button" data-toggle="tooltip" onclick="$('#form-information').submit();" title="<?php echo $button_save; ?>" class="btn btn-primary"><i class="fa fa-save"></i></button>