Amazing that years later ESRI still hasn't addressed this bug despite the functionality becoming standard: https://community.esri.com/t5/arcgis-survey123-questions/bug-body-esri-visible-not-working-for-image...
You'll have to use the same solution we've all been using for 2 years - put the image into a group and hide the group.
The abstruse and intrusive process that ESRI has in place to report bugs, requiring users to have their IT department set up a special account and then provide ESRI with personal contact information means that the odds of anyone actually reporting a bug like this is small.
If the process had been set up so that bugs wouldn't have to be acknowledged, it wouldn't have been done better.