View custom parameters called 'key" still work but disappear.
Right-click the property and enable the option that says Persistent. This should be set by default, but if your project is old enough you may have some residual prop configs that didn’t have this set correctly especially with a parameter called “key” since that’s the default name of any new property.
New project, and if I change the name to other than “key” it stays visible without any other changes.
If setting the key to persistent didn’t fix it, then can you copy the json of the view and send it over? You can do this by Shift+Right-Clicking the view in the project browser and selecting Copy JSON.