No plot associated with Poisson model

I ran breakaway on a frequency count table I have. It selected the Poisson model. When I try to plot the estimated_richness I get NULL as opposed to what happens in the intro vignette. Is this expected behavior? My breakaway version is 4.6.16.

ft <- data.frame(Var1=1:33,Freq = c(684036, 38866, 12840, 6454, 3818, 
2575, 1893, 1354, 1042, 843, 688, 537, 433, 344, 337, 267, 221, 
207, 172, 144, 138, 115, 99, 82, 74, 68, 47, 65, 41, 37, 30, 
32, 27))
estimated_richness <- breakaway(ft)
> plot(estimated_richness)
NULL
> estimated_richness$model
[1] "Poisson"

> R.version
               _                           
platform       x86_64-apple-darwin15.6.0   
arch           x86_64                      
os             darwin15.6.0                
system         x86_64, darwin15.6.0        
status                                     
major          3                           
minor          6.2                         
year           2019                        
month          12                          
day            12                          
svn rev        77560                       
language       R                           
version.string R version 3.6.2 (2019-12-12)
nickname       Dark and Stormy Night 

> sessionInfo()
R version 3.6.2 (2019-12-12)
Platform: x86_64-apple-darwin15.6.0 (64-bit)
Running under: macOS Mojave 10.14.6

Matrix products: default
BLAS:   /System/Library/Frameworks/Accelerate.framework/Versions/A/Frameworks/vecLib.framework/Versions/A/libBLAS.dylib
LAPACK: /Library/Frameworks/R.framework/Versions/3.6/Resources/lib/libRlapack.dylib

locale:
[1] en_US.UTF-8/en_US.UTF-8/en_US.UTF-8/C/en_US.UTF-8/en_US.UTF-8

attached base packages:
[1] parallel  stats4    stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
 [1] vegan_2.5-6                 lattice_0.20-41             permute_0.9-5               pheatmap_1.0.12            
 [5] gridExtra_2.3               DESeq2_1.26.0               SummarizedExperiment_1.16.1 DelayedArray_0.12.3        
 [9] BiocParallel_1.20.1         matrixStats_0.56.0          Biobase_2.46.0              GenomicRanges_1.38.0       
[13] GenomeInfoDb_1.22.1         IRanges_2.20.2              S4Vectors_0.24.4            BiocGenerics_0.32.0        
[17] forcats_0.5.0               stringr_1.4.0               dplyr_0.8.5                 purrr_0.3.4                
[21] readr_1.3.1                 tidyr_1.0.2                 tibble_3.0.1                ggplot2_3.3.0              
[25] tidyverse_1.3.0             magrittr_1.5                breakaway_4.6.16           

loaded via a namespace (and not attached):
  [1] colorspace_1.4-1       ellipsis_0.3.0         htmlTable_1.13.3       XVector_0.26.0         base64enc_0.1-3       
  [6] fs_1.4.1               rstudioapi_0.11        farver_2.0.3           bit64_0.9-7            AnnotationDbi_1.48.0  
 [11] fansi_0.4.1            lubridate_1.7.8        xml2_1.3.2             codetools_0.2-16       splines_3.6.2         
 [16] geneplotter_1.64.0     knitr_1.28             ade4_1.7-15            Formula_1.2-3          jsonlite_1.6.1        
 [21] phyloseq_1.30.0        annotate_1.64.0        broom_0.5.6            cluster_2.1.0          dbplyr_1.4.3          
 [26] png_0.1-7              compiler_3.6.2         httr_1.4.1             backports_1.1.6        assertthat_0.2.1      
 [31] Matrix_1.2-18          cli_2.0.2              acepack_1.4.1          htmltools_0.4.0        tools_3.6.2           
 [36] igraph_1.2.5           gtable_0.3.0           glue_1.4.0             GenomeInfoDbData_1.2.2 reshape2_1.4.4        
 [41] Rcpp_1.0.4.6           cellranger_1.1.0       vctrs_0.2.4            Biostrings_2.54.0      multtest_2.42.0       
 [46] ape_5.3                nlme_3.1-147           iterators_1.0.12       xfun_0.13              openxlsx_4.1.4        
 [51] rvest_0.3.5            lifecycle_0.2.0        XML_3.99-0.3           zlibbioc_1.32.0        MASS_7.3-51.6         
 [56] scales_1.1.0           hms_0.5.3              biomformat_1.14.0      rhdf5_2.30.1           RColorBrewer_1.1-2    
 [61] yaml_2.2.1             memoise_1.1.0          rpart_4.1-15           RSQLite_2.2.0          latticeExtra_0.6-29   
 [66] stringi_1.4.6          genefilter_1.68.0      foreach_1.5.0          checkmate_2.0.0        zip_2.0.4             
 [71] rlang_0.4.6            pkgconfig_2.0.3        bitops_1.0-6           evaluate_0.14          Rhdf5lib_1.8.0        
 [76] labeling_0.3           htmlwidgets_1.5.1      bit_1.1-15.2           tidyselect_1.0.0       plyr_1.8.6            
 [81] R6_2.4.1               generics_0.0.2         Hmisc_4.4-0            DBI_1.1.0              pillar_1.4.4          
 [86] haven_2.2.0            foreign_0.8-76         withr_2.2.0            mgcv_1.8-31            survival_3.1-12       
 [91] RCurl_1.98-1.2         nnet_7.3-14            modelr_0.1.7           crayon_1.3.4           rmarkdown_2.1         
 [96] jpeg_0.1-8.1           locfit_1.5-9.4         grid_3.6.2             readxl_1.3.1           data.table_1.12.8     
[101] blob_1.2.1             digest_0.6.25          reprex_0.3.0           xtable_1.8-4           munsell_0.5.0

adw96 / breakaway

No plot associated with Poisson model #88