Installing qubes-input-proxy-sender in the template it was. Problem
solved. Thanks awokd!
Note: to avoid this problem, these should either be default installed
packages in all templates, or be documented in
https://www.qubes-os.org/doc/usb-qubes/. If the latter is preferred, I
can adapt the
Dear Qubes Community,
The Xen Project has released one or more Xen Security Advisories (XSAs).
The security of Qubes OS *is not affected*.
Therefore, *no user action is required*.
XSAs that affect the security of Qubes OS (user action required)
