Certain mobile phone keyboard shutdown during checkout address fill up

-- HikaShop version -- : 3.2
-- Joomla version -- : 3.7.2
-- PHP version -- : 5.6

Dear

We face a major issue on hikashop checkout during mobile phone

1. while user is filling up the address during checkout keyboard is shutdown (joomla contact form and other website dun have this problem)

2. happen only in certain model of phone (so far find out redmi, samsung note 5, huawei p9 & p9 plus)

we believe this is due to the onchange javascript cause this problem......any adhoc method to disable it ?


some updated findings - the problem gone when i do beolowin index.php, is it possible to do this only in the address fill up step?
<?php
// unset a single js file
unset($this->_scripts);
?>