Customers report cannot see iframe content

Customers report cannot see iframe content

I have started getting reports over the last few weeks that people cannot see the iframe inserted on a page.

I insert my on a website using the publish range and insert the iframe code, so I can update the prices within zoho.

This has worked OK for years, but recently people are saying they can't see the iframe, and they seem to be increasing numbers.

Sometimes Safari, sometimes Internet Explorer, never Chrome and it works OK on iPhones and iPads.

Has something changed? Is anyone else having this issue?