The trick with this is that sometimes (especially with large templates or parameterized screens) you might have the same reference multiple times in the template (for example, engineering units) and it would be nice to only have to define the indirect tag once (template internal property) and then use that value throughout the template.
@taohongyu88 I think that I’ve had similar issues to you with 8.0.12. Are you getting tags that look like this?
I think there is an intermittent issue with Ignition where if you create parameter on a screen, bind it to an indirect tag, and then do a property binding (to the indirect tag parameter) on a screen element that the tag will occasionally not update properly. I do recommend at least trying to remove the property binding and going fully to indirect tag bindings and try to see if that helps.