Find cannot index "Hidden visitor profiling" form element

Description

1. Install the Alloy Template (Cms 10.2.0, Find 12.2.9, Form 4.1.0)
2. Add a hidden visitor profiling element to the form.
3. Add the form to a page.
4. Run the find content indexing job.

Expect: Everything works fine.

Actual: Error like below:

Indexing job [Global assets and other data] [content]: Reindexing completed. ExecutionTime: 0 hours 0 minutes 5 seconds Number of contents indexed: 122 Number of content errors: 1
DESKTOP-ACMVQTF: An exception occurred while indexing content 166: Error getting value from 'AttributesString' on 'Castle.Proxies.VisitorDataHiddenElementBlockProxy'. (see log for more information)

5. Remove the hidden visitor profiling element and re-run to make the error go away.