Strange formatting of legend in ggplotly in R

I'm trying to turn a ggplot into a plotly. The ggplot renders fine, but when I put it through ggplotly, suddenly the legend adds parenthesis and ",1" after the label.

Here's a sample fake data:

sorted1<-data.frame(CommDate=c(as.Date("2017-09-12"), as.Date("2017-10-15")), CommName=c("Foo", "Bar"), PubB4=c(2,3))

And here's the code I'm trying to run on it:

ggplotly(ggplot(sorted1, aes(x=as.Date(CommDate), y=PubB4))+
           geom_smooth(level=0.0, aes(colour="Moving average"), se=FALSE)+
           geom_point(aes(fill=CommName), size=4)+
           expand_limits(y=c(0,4.5))+
           geom_line(mapping=aes(y=4),colour="orangered3",size=1)+
           geom_text(mapping=aes(y=4.2, x=min(sorted1$CommDate)+4), label="Target", size=3)+
           xlab("Committee Date")+
           guides(fill=guide_legend(title="Committee Names"), colour=guide_legend(title.theme=element_blank(),title=NULL))+
           scale_x_date(labels = date_format("%b-%y"))+
           theme_light()+
           theme(plot.title=element_text(hjust=0.5, size=12),panel.grid.major.x = (element_blank()), 
                 panel.grid.minor.x = (element_blank()), 
                 axis.title = element_text(size=8), legend.title = element_text(size=10),
                 legend.text = element_text(size=8), legend.box = 'vertical', legend.spacing.y = unit(-2,"mm"))+
           scale_colour_manual(name="",values="#0072B2"))

(the geom_smooth doesn't render here, but it does with the full data.)

Here's what I get from this:

Why does the legend show up as "(foo,1)"?

I tried removing the geom_smooth which actually solved the problem, but I need it there - how can I keep it but fix the legend?

Thanks!

Update: OK, I started commenting out stuff to see what happens. If I remove the aes() from the geom_smooth, that also fixes the problem, as long as I keep the scale_colour_manual commented off as well. But I really would like to have control over the geom_smooth's aesthetics, and include it in the legend. So I'm making progress, but still not quite there...

Here's yet another elegant solution. Under the hood it detects if a plotly legend name option is available and if so, removes the "(" and ",1)".

library(ggplot2)
library(plotly)
library(stringr)
library(dplyr)

data = data.frame(Date=as.Date(c("2017-09-12","2017-10-15")), PubB4=c(2,3), category=c("Foo", "Bar"))

myplot = ggplotly(ggplot(data, aes(x=Date, y=PubB4))+
    geom_hline(aes(yintercept=2.5, color="my line label"))+
    geom_point(aes(fill=category), size=4))

for (i in 1:length(myplot$x$data)){
    if (!is.null(myplot$x$data[[i]]$name)){
        myplot$x$data[[i]]$name =  gsub("\\(","",str_split(myplot$x$data[[i]]$name,",")[[1]][1])
    }
}

myplot