Xcode 8.3.3 missing line numbers

I recently installed High Sierra 10.13 beta 2 and Xcode 9 beta 2, but still need to use Xcode 8.3.3 for submitting builds to the App Store. While Xcode 9 shows line numbers in the editor, they have disappeared from Xcode 8.3.3 in this configuration. Toggling 'Show: Line numbers' in preferences (of either verision) has no effect. Has anyone else seen this behavior and been able to fix it? Minor, yes. Annoying, yes. Thanks in advance.