Please try to provide as much details as possible in an initial post, this could include e.g. used Linux-Distro, versions of the components in use and similar information which could help other readers to help you.
For your current problem it would be great if you could provide the following info:
What happens with the progress bar during the scan? At least to me its currently not clear if it stays for a longer time at 1% and then jumps to “Complete” or if it is just staying there at 1% without moving forward at all.
Note: Depending on your chosen “Alive Test” method and the port list (e.g. including UDP ports in your port list) it might be completely “normal” that a scan stays a longer time at 1% (this is the port scanning phase) and then goes directly to “Completed” if no open ports / available services where identified.
Which Linux-Distro are you using?
Which versions of the OpenVAS/GVM components are you using? Note: Please name the detailed versions of openvas-manager, openvas-scanner, openvas-libraries, not just “OpenVAS 9”.
Anything in your logfiles (Might be in /var/log/openvas/ depending on your install path)?
Which results are you getting in the report of this specific target?