diffcyt differential expression model with patient_id as random effect only returns NA p values

[singlecellfan]

Hi,

I have followed the tutorial and so far all differential expression analyses worked if I did not specify a random variable.
This is how the ds_formula2 looks for me.

diffcyt(sce, formula = ds_formula2, contrast = contrast, analysis_type = "DS", method_DS = "diffcyt-DS-LMM", clustering_to_use = "merging_all", verbose = FALSE)

Has this occured before? I am not sure what the problem might be, as the differential expression works fine without specifying a random effect.

Thanks!