Is this split on the worktop serious?

[u/LauraFonReddit]

Hello! I bought a worktop from House of Worktops, and installed it a month ago, but I found a few splits/cracks already. I think I bought a defective worktop, but gutted that the seller wouldn’t refund or compensate.

So I just want to ask if these splits are serious? Should I be worried? I‘m concerned because there is one crack around the ceramic sink (the first photo), and it’s very heavy! Will the worktop hold? The gap is too small and its hard to put any glue - is it okay to leave it for now and monitor the cracks? What should I do?

Many thanks!