I have a monthly time series data of 3 years whose acf and pacf plots confirms absence of seasonality. But auto.arima picks a seasonal model by seasonal difference first and then seasonal AR component and then it gives warning that seasonal difference will not be done.
Can anyone please explain why even seasonal seasonal model is selected and the warning below which just contradicts what auto.arima did?
ACF plot: No seasonal lags significant
EDIT : Data provided
forecast package version is 8.5
library(forecast) data_ts <- ts(c(858202,1268645,1483015,1469438,1316090,1240012,1148112,1557396,1210394,1298259,1146520,1205847,1612222,2206315,2380862,2009639,1628334 ,2084517,2672135,1706195,1726972,1749780,1859735,1727888,2745657,2383249,2969345,3106084,2441399,2069020,2602255,3016157,2137989,2129232 ,2223055,2202366),frequency = 12,start = c(2016,01)) auto.arima(data_ts)