I also tried many things to reproduce the bug. Calling this UI 100 times a second, adding a bunch of assets to make the scene heavier, adding many creature spawners and attacking them with a ray gun, getting other HUD messages on the screen, or updating other UI at the same time, but nothing really makes it easy to reproduce.
Opening many Chrome tabs and playing a bunch of YouTube videos has been the most reliable, while spawning the ui 100 times a second, but still takes a while.
Let me know if I can help by sharing my code, good luck!