There have been several postings here where someone is trying to get a Grove-Pi/Grove-Pi+ working and it fails no matter what they try.
The eventual root cause of this failure is that the individual downloaded and installed Raspbian Bullseye.
It should be noted that the Dexter Industries libraries for the Grove-Pi are not yet compatible with Bullseye.
The solution is to flash your SD card with the Raspbian Buster image located here:
Then run the “curl” commands in the installation guide for the Grove-Pi.
If you are using a Pi-4, this version of Raspbian is mandatory as other, earlier, versions will not boot on the Raspberry Pi-4.
Updated the link to point to the official download site for the “legacy” version of Raspbian.