Duplicated factor levels while calling stratify()

[fka21]

Hello. When calling the stratify function I get an error message of
Error in levels<-(tmp, value = as.character(levels)) : factor level [20] is duplicated

The code used was
focal_taxid <- '7230'
str_dmoj <- strata_from_blast_dir(focal_taxid, blastdir = "/Users/ferenckagan/Documents/Bioinformatic_analysis/phylostratr_proteomes/Comparative_phylostrat/7230", ext = "tab") %>% strata_besthits()
results_dmoj <- strata_convert(str_dmoj, target = 'all', to = 'name') %>% merge_besthits()
str_dmoj <- stratify(results_dmoj, strata_names = get_mrca_names(results_dmoj))

I tried to check the results table for any anomalies but could not find anything in particular at the ps 20 compared to the rest of phylostrata. In parallel I have read in other blast outputs from other focal species without any problems so the issue is in this particular blast result. Do you have any ideas what could cause the problem?

Thank you very much in advance for the help.

Cheers,
Ferenc