Column width does not respond propely in a ggplot2 heatmap after using ggplotly()

I have this data frame:
gene_symbol<-c(“DADA”,“SDAASD”,“SADDSD”,“SDADD”,“ASDAD”,“XCVXCVX”,“EQWESDA”,“DASDADS”,“SDASDASD”,“DADADASD”,“sdaadfd”,“DFSD”,“SADADDAD”,“SADDADADA”,“DADSADSASDWQ”,“SDADASDAD”,“ASD”,“DSADD”)
panel<-c(“growth”,“growth”,“growth”,“growth”,“big”,“big”,“big”,“small”,“small”,“dfgh”,“DF”,“DF”,“DF”,“DF”,“DF”,“gh”,“DF”,“DF”)
ASDDA<-c(“normal”,“over”,“low”,“over”,“normal”,“over”,“low”,“over”,“normal”,“over”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”)
ASDDb<-c(“normal”,“over”,“low”,“over”,“normal”,“over”,“low”,“over”,“normal”,“over”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”)
ASDDAf<-c(“normal”,“over”,“low”,“over”,“normal”,“over”,“low”,“over”,“normal”,“over”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”)
ASDDAf1<-c(“normal”,“over”,“low”,“over”,“normal”,“over”,“low”,“over”,“normal”,“over”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”)
ASDDAf2<-c(“normal”,“over”,“low”,“over”,“normal”,“over”,“low”,“over”,“normal”,“over”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”)
ASDDAf3<-c(“normal”,“over”,“low”,“over”,“normal”,“over”,“low”,“over”,“normal”,“over”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”)
ASDDAf4<-c(“normal”,“over”,“low”,“over”,“normal”,“over”,“low”,“over”,“normal”,“over”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”)
ASDDAf5<-c(“normal”,“over”,“low”,“over”,“normal”,“over”,“low”,“over”,“normal”,“over”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”)
ASDDA1<-c(“normal”,“over”,“low”,“over”,“normal”,“over”,“low”,“over”,“normal”,“over”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”)
ASDDb1<-c(“normal”,“over”,“low”,“over”,“normal”,“over”,“low”,“over”,“normal”,“over”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”)
ASDDAf1<-c(“normal”,“over”,“low”,“over”,“normal”,“over”,“low”,“over”,“normal”,“over”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”)
ASDDAf11<-c(“normal”,“over”,“low”,“over”,“normal”,“over”,“low”,“over”,“normal”,“over”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”)
ASDDAf21<-c(“normal”,“over”,“low”,“over”,“normal”,“over”,“low”,“over”,“normal”,“over”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”)
ASDDAf31<-c(“normal”,“over”,“low”,“over”,“normal”,“over”,“low”,“over”,“normal”,“over”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”)
ASDDAf41<-c(“normal”,“over”,“low”,“over”,“normal”,“over”,“low”,“over”,“normal”,“over”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”)
ASDDAf51<-c(“normal”,“over”,“low”,“over”,“normal”,“over”,“low”,“over”,“normal”,“over”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”,“DF”)
Gene_states22 <- data.frame(gene_symbol, panel, ASDDA, ASDDb, ASDDAf, ASDDAf1, ASDDAf2,
ASDDAf3, ASDDAf4, ASDDAf5, ASDDA1, ASDDb1, ASDDAf1, ASDDAf11,
ASDDAf21, ASDDAf31, ASDDAf41, ASDDAf51)

#And I create a heatmap with:

library(plotly)
library(ggplot2); library(reshape2)
HG3 <- split(Gene_states22[,1:15], Gene_states22$panel)
HG4 <- melt(HG3, id.vars= c("gene_symbol","panel"))
HG4 <- HG4[,-5]
HG5 <- split(HG4, HG4$panel)
pp <- ggplot(HG4, aes(gene_symbol,variable)) + 
  geom_tile(aes(fill = value),
            colour = "grey50") + 
  facet_grid(~panel, scales = "free") +
  scale_fill_manual(values = c("white", "red", "blue", "black", "yellow", "green", "brown")) +
  labs(title = "Heatmap", x = "gene_symbol", y = "sample", fill = "value") +
  guides(fill = FALSE)+
  theme(panel.background = element_rect(fill = NA),
        panel.spacing = unit(0.5, "lines"), ## It was here where you had a 0 for distance between facets. I replaced it by 0.5 .
        strip.placement = "outside")

ggplotly(pp,
         width = 1350, height = 600) %>%
  # note: specifying width / height in layout() has been deprecated
  # in recent versions of plotly. when I used it that way, I got
  # a warning to specify it within ggplotly() instead.
  layout(autosize = F, 
         hoverlabel = list(bgcolor = "white",
                           font = list(family = "sans serif", size = 9, color = "black")))

As you can see this heatmap is separated into 6 sub-heatmaps depending on the panel. Every panel contains some gene_symbol. Right now the column widths difer in size in each panel. What I would like to do is to make the column widths all the same regardless of the number of genes in each panel.

Before using ggplotly()

After using ggplotly()

I think it is clear that ggplotly() causes the issue with the column width.