This would have been my suggestion as well:
The github master branches are development versions not officially released and where all the development is happening. Such versions might show unexpected behavior or could even break/be in a temporary unusable state at any time.
In your case it seems you even have used a master branch on a state before the final GVM 10 release which could be an additional reason for this behavior.
For productive use it is strongly suggested to stay with the official announced source code releases in About the Greenbone Source Edition (GSE) category.