Sorry for the delayed response to this. If Autotune was recommending https and wasn't before, it likely means that either a) you just added a valid SSL cert to your site or b) you previously ran Autotune while logged into your admin area in non-https mode.
We haven't heard any other issues with Autotune lately, so not sure what's happening there. What I'd recommend is:
* Testing again, of course. It's possible there was just a hiccup with Facebook when you tried previously
* Login to your site over http (non-SSL), if possible, and try to run Autotune. See if the http only values are able to be saved
* Test the front-end in general and see if there are any problems, even if you can't save. Hopefully all is well and it's just a glitch that you can ignore for now.
As always, you can edit your Facebook's App settings in the FB Developer area if necessary. Not as much fun, but do-able if you need to make a change that you can't do through Autotune for some reason.
I hope that helps,
Alex
Facebook API error on update to JFB Connect 6.0.3
