Hi,
The 2.2.3 release does not remove the "add to cart" buttons. Please check your configuration.
We cannot access to your website so it will be difficult for us to see the problem.
Are you sure that you did not activate the "catalog mode" by mistake ?
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.