My lexicon collection is type:lexicon rating:>1; embraces Greek/Hebrew/Aramaic languages and 19/26 lexicons. About 20% of the time All Parallel Resources is not displayed for a headword in DBL Greek/DBL Hebrew, Louw-Nida eg. κρίνω, יַעְנַי. But if i go back it will display All Parallel Resource. So it is not specific to a word. It can be the first headword when (re)visiting the resource.
Parallel Resources display for a lexicon headword is faster in B3, although not predicted to be so in the Release Notes - perhaps something to do with the new lexicon Field?