Проверьте, готов ли документ JS
if( document.readyState !== 'loading' ) {
console.log( 'document is already ready, just execute code here' );
myInitCode();
} else {
document.addEventListener('DOMContentLoaded', function () {
console.log( 'document was not ready, place code here' );
myInitCode();
});
}
function myInitCode() {}
Anthony Smith