This is how vaccine breakthrough cases develop. This doesn’t mean that vaccines aren’t working. But we should all be aware that they have some limitations. Still, it’s important that as many people as possible should get their full course of vaccination, because a fully vaccinated individual typically clears the infection faster than someone who is not vaccinated or received only one dose.
Therefore, vaccines are preventing the infection from causing worse symptoms for those who are vaccinated and still contract the virus, while they also shorten the period in which a vaccinated person is likely to be infectious and thus reduces their likelihood of passing the virus on.