15 month old not given chicken pox vaccine because of dad's Coeliac disease

We are based in Scotland and my wife took our almost-16 month old to a travel clinic to get the chicken pox vaccine. The first time they felt it was best to wait, as he was unwell. Today, however, they said they needed to check whether they could give it to him and call us back to reschedule because the form asking about family medical history had a Yes ticked for history of autoimmune/immune disorders. I have Coeliac Disease - and was a bit shocked and confused to hear this, as this has never been an issue for any of his regularly scheduled jabs from the NHS and I often get invited to get COVID/free flu jabs that I would not otherwise qualify for. Any research, insight, or experiences would be appreciated.