Hi,
from the screenshot I can see you are using GVM/OpenVAS 9 which is outdated and unsupported since some time already (GVM-9 (end-of-life, initial release 2017-03-07)). It is very very likely that your issue has already been fixed in a newer version. The current and only supported version is GVM 20.08 (stable, initial release 2020-08-12)