I did the same web search (although in all caps) and was immediately pointed to “Commercial of-the-shelf”, and I redid it now in incognito mode over a VPN, and

I did the same web search (although in all caps) and was immediately pointed to “Commercial of-the-shelf”, and I redid it now in incognito mode over a VPN, and the first answer is still “ Commercial-off-the-shelf” (with an added hyphen probably due to the language where the VPN endpoint is located.)