I have found another example of misdetection of GPL-3
In most of the files in https://sources.debian.org/src/xbrzscale/1.8-2/xbrz/ the license is given in the line// * GNU General Public License: https://www.gnu.org/licenses/gpl-3.0 *
but licensecheck detects as just GPL. Changing the case to GPL-3.0 does not improve things.
