Pasted "X" not showing on my graph using plot()

Question

I am trying to plot a graph where one point is showing different from the others. I have written this code, however the pasted symbol "X" for the certain point that I have indicated is showing a partial symbol. I have tried changing the size, symbol, even just using a different pct for the number, and it still shows partially.

plot(xcoord,ycoord,pch=20,col="gray",xlab="Latitude",ylab="Longitude",
     main="Map of Extreme Changing NDVI")
for (i in 1:49681){
  if(pvals[i] < 0.01 & slopes[i]==1) points(xcoord[i],ycoord[i], 
    pch=ifelse(i==777,paste("X",font=5),20), cex=ifelse(i==777,1.5,0.5), col=ifelse(i==777,"darkgreen","green"))
  if(pvals[i] < 0.01 & slopes[i]==-1) points(xcoord[i],ycoord[i], 
    pch=ifelse(i==2037,paste("X",font=5),20), cex=ifelse(i==2037,1.5,0.5), col=ifelse(i==2037,"brown4","red"))
  if(pvals[i] > 0.01) points(xcoord[i],ycoord[i], pch=20, cex=0.5, col="tan")
}

View of graph that is showing the partial symbols