Hi,
You put the same canonical url for the two products, so they got the same SEF url : /product/a-moment-in-time-clocks
When you call this url, HikaShop will find the first product with that canonical url, but if there are two products, one won't be accessible.
So you have to change the product canonical urls for these products.
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.