How to remove mysterious tilda from Plotly's tooltip?


I’m using R’s ggplot and passing it through ggplotly to generate interactive charts on my Shiny app. However, I have no idea why my tooltip keeps displaying a “~” sign before the variable name and I can’t seem to remove it. This appears for all my charts in my Shiny app. How can I remove the “~”?

Can anyone help?

Zhan Hao