Why does datafreme error after using GRfit for grouping?

Question

I saw error in R-script.

library(GRmetrics)
df <- read.csv("E:/Result 2023-1-19/KKU100.csv")
head(mydata) 
df1 <- na.omit(df)

drc_output = GRfit(df1, groupingVariables = c('cell_line','treatment'))
drc_output

and the error is :

Error in `$<-.data.frame`(`*tmp*`, "r2_GR", value = c(0.832500851136755,  : 
  replacement has 6 rows, data has 7
In addition: There were 12 warnings (use warnings() to see them)

in other result I can get the GR-curve

drc_output = GRfit(mydata, groupingVariables = c('cell_line','treatment'))
drc_output

I will get the data like this:

drc_output
class: SummarizedExperiment 
dim: 19 5 
metadata(2): '' ''
assays(1): ''
rownames(19): ctrl_cell_doublings GR50 ... pval_rel_cell flat_fit_rel_cell
rowData names(2): Metric Description
colnames(5): SSP25 Afatinib SSP25 Evolimus SSP25 Lapatinib SSP25 Mubritinib SSP25
  Tuxobertinib
colData names(6): cell_line treatment ... experiment concentration_points