Installing ibus on Debian has a tendency to stop the keyboard working, particularly in KDE system dialogue boxes and search feilds. ibus is not really required, so patching the deb to prevent the install from also installing ibus as a required dependecy solves the problem:
S=$(mktemp -d)
dpkg -x zoom_amd64.deb $S
dpkg -e zoom_amd64.deb $S/DEBIAN
sed -i -E 's/(ibus, |, ibus)//' $S/DEBIAN/control
dpkg -b $S zoom_amd64-no-ibus.deb
Original info came from https://hashman.ca/zoom/
Проверено, работает.