Search results show deleted files

Steps to reproduce on a hosted 12.10.6 or 10.11.9 Cloud wiki:
1. Upload file anexa11.pdf and file anexa21.pdf on the Sandbox page.
2. Delete anexa11.pdf
3. Search for "anexa" on the top right search option
4. Uncheck Documents and check Attachments option

Expected result:
Only the anexa21.pdf file appears.

Actual result on the hosted 12.10.6 version:
Both anexa11.pdf and anexa12.pdf appear

Tried as well after that:
5. Deleted from Deleted attachments
6. Searched again

Same result: Both anexa11.pdf and anexa12.pdf appear.

Accessing the resulted anexa11.pdf shows that the file does not exist:

From logs:
Suspecting that Solr is not notified of the deleted attachment because of the failure in

Failed to send event [org.xwiki.bridge.event.DocumentUpdatedEvent@3f6d7d88] to listener [com.xpn.xwiki.internal.event.AttachmentEventGeneratorListener@8bd4d15]

Still a question: why the

deleteattachment

action end up in trying to get the contents of the attachment it has just deleted?

I did not reproduce on a freshly locally downloaded XWiki Jetty HSQLDB 12.10.6, on local Jetty HSQLDB 12.10.8 (current Long Term Support) or local Jetty HSQLDB 13.4. The search after deleting the file anexa11.pdf showed only anexa21.pdf , even if the file anexa11.pdf was not deleted as well from Deleted Attachments