Problem: Timeout issues.
Affects: WFS. All versions.
Description: Features not displayed for some layers due to large number of features and timeout setting.
Workaround: Under Settings/ Options/ Network, change the "Timeout for network requests (ms)" from 60,000 to 180,000. Add reference base layers (WMS/ WMTS) and zoom to area of interest then add WFS layers (make sure the "Cache Feature" is unticked).