I have a similar problem. I tried to solve it, but I didn't have much success. I'm going to paste my code here to see if you can help me.
tempo_1 <- as.character(Sankey$Tempo_1)
Sankey$Tempo_1 <- factor(Sankey$Tempo_1, levels = tempo_1, labels = tempo_1)
tempo_2 <- as.character(Sankey$Tempo_2)
Sankey$Tempo_2 <- factor(Sankey$Tempo_2, levels = tempo_2, labels = tempo_2)
ggplot(Sankey, aes(axis1 = Tempo_1, axis2 = Tempo_2, y = Valor)) +
geom_alluvium(aes(fill = Tempo_1)) +
geom_stratum(aes(fill = NULL), color = NA) +
geom_text(stat = "stratum", aes(label = after_stat(stratum))) +
theme_minimal() +
theme(panel.border = element_blank(), legend.position = "none")
labs(title = "Important Cytokines in time")
