Package: firefox Version: 67.0-3 Followup-For: Bug #929846 Upgrading libnss3 to 3.44 of unstable did fix the issue, so please add it as dependency, like "libnss3 (>= 2:3.44)".
Also, I did not get your suggestion about setting network.http.spdy.enabled.http2 to false. Is it a security concern? Obviously none of the servers I am connecting to has a problem, because all other browsers connect just fine. And I am still connected on the same network I have been in the last 10+ years. -- Package-specific info: -- Extensions information Name: Firefox Monitor Location: /usr/lib/firefox/browser/features/fxmoni...@mozilla.org.xpi Package: firefox Status: enabled Name: Firefox Screenshots Location: /usr/lib/firefox/browser/features/screensh...@mozilla.org.xpi Package: firefox Status: user-disabled Name: Form Autofill Location: /usr/lib/firefox/browser/features/formautof...@mozilla.org.xpi Package: firefox Status: enabled Name: uBlock Origin Location: ${PROFILE_EXTENSIONS}/ublo...@raymondhill.net.xpi Status: enabled Name: Video DownloadHelper Location: ${PROFILE_EXTENSIONS}/{b9db16a4-6edc-47ec-a1f4-b86292ed211d}.xpi Status: enabled Name: Web Compat Location: /usr/lib/firefox/browser/features/webcom...@mozilla.org.xpi Package: firefox Status: enabled Name: WebCompat Reporter Location: /usr/lib/firefox/browser/features/webcompat-repor...@mozilla.org.xpi Package: firefox Status: user-disabled -- Plugins information Name: Shockwave Flash (32.0.0.192) Location: /usr/lib/flashplayer-mozilla/libflashplayer.so Package: flashplayer-mozilla Status: disabled -- Addons package information ii firefox 67.0-3 amd64 Mozilla Firefox web browser ii flashplayer-mozilla 3:32.0.0.192-dmo2 amd64 Adobe Flash Player -- System Information: Debian Release: 10.0 APT prefers testing APT policy: (990, 'testing'), (500, 'unstable'), (1, 'experimental') Architecture: amd64 (x86_64) Kernel: Linux 4.19.0-5-amd64 (SMP w/2 CPU cores) Kernel taint flags: TAINT_PROPRIETARY_MODULE, TAINT_OOT_MODULE, TAINT_UNSIGNED_MODULE Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE=en_US:en (charmap=UTF-8) Shell: /bin/sh linked to /bin/dash Init: systemd (via /run/systemd/system) Versions of packages firefox depends on: ii debianutils 4.8.6.1 ii fontconfig 2.13.1-2 ii libasound2 1.1.8-1 ii libatk1.0-0 2.30.0-2 ii libc6 2.28-10 ii libcairo-gobject2 1.16.0-4 ii libcairo2 1.16.0-4 ii libdbus-1-3 1.12.12-1 ii libdbus-glib-1-2 0.110-4 ii libevent-2.1-6 2.1.8-stable-4 ii libffi6 3.2.1-9 ii libfontconfig1 2.13.1-2 ii libfreetype6 2.9.1-3 ii libgcc1 1:8.3.0-6 ii libgdk-pixbuf2.0-0 2.38.1+dfsg-1 ii libglib2.0-0 2.58.3-1 ii libgtk-3-0 3.24.5-1 ii libjsoncpp1 1.7.4-3 ii libnspr4 2:4.21-1 ii libnss3 2:3.44-1 ii libpango-1.0-0 1.42.4-6 ii libsqlite3-0 3.27.2-2 ii libstartup-notification0 0.12-6 ii libstdc++6 8.3.0-6 ii libvpx5 1.7.0-3 ii libx11-6 2:1.6.7-1 ii libx11-xcb1 2:1.6.7-1 ii libxcb-shm0 1.13.1-2 ii libxcb1 1.13.1-2 ii libxcomposite1 1:0.4.4-2 ii libxdamage1 1:1.1.4-3+b3 ii libxext6 2:1.3.3-1+b2 ii libxfixes3 1:5.0.3-1 ii libxrender1 1:0.9.10-1 ii libxt6 1:1.1.5-1+b3 ii procps 2:3.3.15-2 ii zlib1g 1:1.2.11.dfsg-1 Versions of packages firefox recommends: ii libavcodec58 10:4.1.3-dmo1 Versions of packages firefox suggests: pn fonts-lmodern <none> pn fonts-stix | otf-stix <none> ii libcanberra0 0.30-7 ii libgssapi-krb5-2 1.17-2 ii libgtk2.0-0 2.24.32-3 pn pulseaudio <none> -- no debconf information