It looks like you have discovered a few bugs, it appears 🙂
Thank you for the correct description and the login information, it made my work much faster.
1. You are right, it was not working correctly, the suggested words were incorrect. I've used the FTP account to do some debugging, and found a programming error, which resulted printing the incorrect word. The word should be relevant and correct now.
To get the autofilled text actually filled, you need to press the right arrow on your keyboard, and it finishes the suggestion. I know it's strange, but when I built the engine, the google suggest used this same method, but now it's different. I will try to work out a better, more convenient solution in the future for sure.
2. Another bug I discovered, that on the layout options panel, when the user login was selected as the user name field, the search did not go through as there was a typing error in the field value. Once I fixed that, it started working as configured. I'm definitely fixing this in the upcoming version, as I was not aware of this tiny issue 🙂
3. Same as the 2. issue, it should be working as well.
4. In this case you need the “Index table” engine. Posts and custom post types related to names can be indexed together, but comments not. So searching for a user name should give you the submitted posts, pages, recipes and q&a stuff which the user posted, but not the regular post comments (those are unfortunately stored differently in wordpress). I see you did configure the index table correctly for this task. I've switched to the index table engine on the search General Options panel to have this in effect.
Another reason to use the index table engine instead of the regular one is the fact that you have the “OR with exact keyword matches” search logic activated – which works far better with the index table engine, as there are no special characters involved in the index table, and therefore the word boundaries are recognized far efficiently. That means more relevant results.
Let me know if you need any more help!Best,
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