As I said earlier, in IRCC systems Family name can not be entered as blank, so they have used your Given name as Family name. Similar is the case with any application to USCIS.
So, now your application looks like this :
| As per your passport | As per IRCC |
Given Name | Harpreet Singh | Blank |
Family Name | Blank | Harpreet Singh |
I have seen similar scenarios with other people as well and I haven't heard that they faced any issues. However, I would recommend to check with any of your friends and family who doesn't have family name and hold a PR card.