In order to stop, reload of you need work on configurable.js
file:
On this js at _configureElement(), you need to remove this._changeProductImage();
this._reloadPrice();
this._displayRegularPriceBlock(this.simpleProduct);
this._displayTierPriceBlock(this.simpleProduct);
this._displayNormalPriceLabel();
//this._changeProductImage(); // remove this line
Who to do it:
First,you should check configurable.js exits at your theme level
means
app/design/frontend/{YourThemeVendor}/{YourThemeName}/Magento_ConfigurableProduct/web/js/configurable.js
If exits then comment the _changeProductImage
.
Or if it does not exits then copy the file from
vendor/magento/module-configurable-product/view/frontend/web/js/configurable.js
then paste at
app/design/frontend/{YourThemeVendor}/{YourThemeName}/Magento_ConfigurableProduct/web/js/configurable.js
Do comment _changeProductImage
.