[BUG]: Some states in a multi-stratified model are not shown correctly as circle-packed nodes

[liunelson]

Describe the bug

I have this model:
https://app.staging.terarium.ai/projects/34e7b955-f408-4e8b-be27-9429480ad6aa/model/7508b278-caea-4d35-bb17-097bdd463f07

It was created by stratifying a base SEIRHD model 4 times consecutively:

1. only the S node, by "vaccination", over two strata ("unvaccinated", "vaccinated")
2. only the S_vaccinated node, by "vaccine", over three strata ("pfizer", "moderna", "jj")
3. only the S_vaccinated_pfizer and S_vaccinated_moderna nodes, by "dose", over three strata ("one", "two", "diff")
4. all nodes except D, by "age", over three strata ("0to9", "10to19", "20above")

Expected behavior
Since the nodes of this model do not have the same stratification depth, I expected to see some nodes like E, I, R, H to have two levels (correct) and D have one (correct), while the S node have more complex structure.

The S node should have 5 levels:

S = [S]
   = [[S_unvaccinated, S_vaccinated]]
   = [[S_unvaccinated, S_vaccinated = [S_vaccinated_jj, S_vaccinated_pfizer, S_vaccinated_moderna]]]
   = [[S_unvaccinated, [S_vaccinated_jj, [S_vaccinated_pfizer_one, S_vaccinated_pfizer_two, S_vaccinated_pfizer_diff], [S_vaccinated_moderna_one, S_vaccinated_moderna_two, S_vaccinated_diff]]]]
   = [[[S_unvaccinated_0to9, S_unvaccinated_10to19, S_vaccinated_20above], [[S_vaccinated_jj_10to19, S_vaccinated_jj_20above]], [[S_vaccinated_pfizer_one_10to19, S_vaccinated_pfizer_one_20above], [[S_vaccinated_pfizer_two_10to19, ...], [S_vaccinated_pfizer_diff_10to19, ...]], [[S_vaccinated_moderna_one_10to19, ...], [...], [...]], [[S_vaccinated_moderna_diff_10to19, ...], [...], [...]]]]]

Screenshots
Current incorrect:

Sketch of the correct structure of each state node