Fake players on scoreboard sidebar don't appear if display was also set to "belowname" that tick

Partner Rank: 3
Verification Builds: 1.8.0.23
Summary: If a scoreboard objective is displayed to belowname then sidebar, fake players will not appear on the sidebar.
Repro Steps: (from video)
1. Download and open the attached world.
2. Click the button labelled "bug."
3. Click the button labelled "no bug."
Observed Results: The first button will show a blank sidebar, the second will show a sidebar with one entry.
Expected Results: Both should show an entry.
Screenshots/Videos attached: Yes
Following repro steps: https://gfycat.com/SmoothImpracticalChihuahua
World download: https://bugs.mojang.com/secure/attachment/193137/MCM-483.mcworld
Notes: The two buttons simply run functions. The difference between the two is that the first sets the objective to belowname before showing it on the sidebar, and the second does not. You can view these functions in the behavior pack.