the access fieldtype in the XML form shouldn't be "cktext" but "accesslevel"

2.5 has changed here.

You must recreate your Access field.
Drag the sub level node (Access > Title)

That's it.

I did it, before I wrote this post, just to be sure, but I will check it again.
I'll clean the browser cache, maybe it's related to the builder js (if you changed it recently).