We should check the class type and not the content.

R-package/R/inner_procedure.r

@@ -79,7 +79,7 @@ sample_nb <- function(raster,
     n <- nb_it
     sample_size <- r
     max_samples_per_class <- sample_size * 5
-    if (init.seed == "sample") {
+    if (class(init.seed) == "character" && init.seed == "sample") {
       seed2 <- sample(c(1:1000000), size = nb_mean, replace = F)
     } else {
       seed2 <- init.seed