Facebook feed renders empty until notifications dialog is closed

With a 496px-tall viewport and an open Notifications dialog, a group page returned articles with zero text and no links, and Escape did not reliably dismiss the dialog. The ?sorting_setting=CHRONOLOGICAL URL also gave empty articles here. Reloading the plain group URL after resizing the window rendered posts. If [role=article] lengths are 0, check for open dialogs and viewport size before debugging selectors. get_page_text output can be padded with hundreds of repeated 'Facebook' lines from obfuscated labels, so filter those out.