I’m not sure if this has something to do with the broken network issue on alpine.
There is a workaround here (alpinelinux/docker-alpine#135 (comment)) which requires raspberry pi users to upgrade to a newer libseccomp2 from Debian Buster until Raspbian upgrades:
wget http://ftp.de.debian.org/debian/pool/main/libs/libseccomp/libseccomp2_2.5.1-1_armhf.deb
dpkg -i libseccomp2_2.5.1-1_armhf.deb
Edit: upgrade libseccomp2 to 2.5.3-2 package; 2.5.1-1 is unavailable
wget http://ftp.de.debian.org/debian/pool/main/libs/libseccomp/libseccomp2_2.5.3-2_armhf.deb
dpkg -i libseccomp2_2.5.3-2_armhf.deb