Metamask issue connecting

I have a claim page open and I’ve had 2 collectors say they were not able to claim my NFT as it would not connect to their metamask. Not sure what can be done about this? But I thought I’d inform you.
This is the claim page

When you say they were not able to connect to their MetaMask, could you expand a bit more? What do they mean by that? What device and browser where they using?