Sequence analysis clustering CHI2 EUCLID error

I am quite new to sequence analysis and trying to identify clusters in an aggregated sequence matrix, focusing on the state duration. However, when using method='CHI2'/'EUCLID' combined with step=1 (not otherwise) I am getting the error:

Error in if (SCres > currentSCres) { : missing value where TRUE/FALSE needed

Any ideas why (there are some NaN in the distance matrix, could they result from sequences being of different length)?

What the sequence object and distance matrix looks like Code:

Sequence                                         
1    a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a
2    a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a  
3    a-e-e-e-e-e-e-e-e-e-e-e-e-e-e-e-e-e-e-e-e-e-c-c-c
4    a-e-e-e-e-e-e-e-e-e-e-e-e-e-e-e-e-e-e-e-e-e-e-e-e
5    b-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a-a

Distance matrix
           1         2      3          4
2        NaN                              
3        289.92897   NaN                    
4        141.07472   NaN    263.22855          
5        10.22425    NaN    290.10919  141.44473

Code:

library(TraMineR) #version 2.0-13
library(WeightedCluster) #version 1.4

SO = seqdef(DAT,right='DEL')
DM = seqdist(SO, method = "CHI2", step=1, full.matrix = F)
FIT = seqpropclust(SO, diss=DM, maxcluster=8, 
      properties=c("state", "duration", "spell.age","spell.dur",
        "transition","pattern", "AFtransition", "AFpattern","Complexity"))