@drubb I have run into the similar issue, in my case it was 'node:entity' and my index didn't use node:entity.
But when I looked at the yml file for the search_api_autocomplete for that index I saw in the yml node:entity config.
In the UI there were no settings for the node:entity but in the yml file there was.
Cleaning up manually yml file and removing all things related to node:entity and then importing the config resolved my issue. This needs to be done carefully and checking the dependancies, fields, view_modes basically entire file and making sure that it is correctly adjusted and that config can be imported after the changes are done.
I presume that at some point the index also included the node:entity but when it was removed from the index search_api_autocomplete yml file was not updated to remove the rows relating to node:entity. Just looking at the UI you would not be able to see this.
So there is a good chance that there is a different issue of search_api_autocomplete files not getting updated when related index is updated by removing one of the previously indexed entities.
Tested and can confirm all is working as expected on Drupal 10.
This patch is working for me as well.
Tested and all is working as expected.
Here is a patch that resolves the issue.
Sumi → created an issue.
Tested and it is working as expected. Issue with Bootstrap layout builder is fixed.