It seems that the source of the error was the following: I made changes to the metainfo in my computer to fix the issue, but did not push them, and flatpak builder was building from the remote git repo where the issue was not patched.
It seems that the source of the error was the following: I made changes to the metainfo in my computer to fix the issue, but did not push them, and flatpak builder was building from the remote git repo where the issue was not patched.