I guess it's because the old HWiNFO version didn't support Corsair Link devices, while the new ones do.
And the problem is when any other tool tries to access a Corsair device while the Corsair Link software is running - it can cause conflicts.
We (and other developers) have asked Corsair to implement a simple mechanism to avoid this. They promised it, but haven't done yet. It has been discussed several times on their forum.
If you want to see Corsair information in HWiNFO you need to close the Corsair Link software. Otherwise disable monitoring of the Corsair device in HWiNFO. Or wait for an update from Corsair that will address this issue.