`ERROR: KeyError: key 'ᵢ' not found` when using subscripts with QuantumCumulants.jl

[oameye]

using QuantumCumulants, HarmonicBalance
HB = HarmonicBalance;

# two bosonic modes
h1 = FockSpace(:cavity)
h2 = FockSpace(:cavity)
# tensor their hilbert spaces
h = h1 ⊗ h2

# specify which subspace
@qnumbers a₁::Destroy(h, 1) a₂::Destroy(h, 2)
param = @variables ω₁::Real ω₂::Real ω::Real K₁::Real K₂::Real g::Real F::Real γ::Real

H₁ = -(ω - ω₁) * a₁' * a₁ + K₁ * (a₁'^2) * (a₁^2) + F * (a₁' + a₁)
H₂ = -(ω - ω₂) * a₂' * a₂ + K₂ * (a₂'^2) * (a₂^2)
H = H₁ + H₂ + g * (a₁' * a₂ + a₂' * a₁)


ops = [a₁, a₂];
mf_eqs = complete(meanfield(ops, H, order=1))

# find steady states with harmonicbalance
fixed = (g => 0.001, ω₁ => 1, ω₂ => 1.1, K₁ => 1.0, K₂ => 1.0, γ=>0.001)
varied = (ω => range(0.9, 1.2, 100), F => range(1e-5, 2.0, 100))
problem = HarmonicSteadyState.HomotopyContinuationProblem(mf_eqs, param, varied, fixed)

ERROR: KeyError: key 'ᵢ' not found
Stacktrace:
  [1] getindex
    @ ./dict.jl:498 [inlined]
  [2] #15
    @ ~/.julia/packages/HomotopyContinuation/Cibx5/src/model_kit/symbolic.jl:20 [inlined]
  [3] iterate
    @ ./generator.jl:47 [inlined]
  [4] collect_to!
    @ ./array.jl:892 [inlined]
  [5] collect_to_with_first!
    @ ./array.jl:870 [inlined]
  [6] _collect(c::Vector{…}, itr::Base.Generator{…}, ::Base.EltypeUnknown, isz::Base.HasShape{…})
    @ Base ./array.jl:864
  [7] collect_similar
    @ ./array.jl:763 [inlined]
  [8] map
    @ ./abstractarray.jl:3286 [inlined]
  [9] (::HomotopyContinuation.ModelKit.var"#14#18")(str_index::SubString{String})
    @ HomotopyContinuation.ModelKit ~/.julia/packages/HomotopyContinuation/Cibx5/src/model_kit/symbolic.jl:20
 [10] iterate
    @ ./generator.jl:47 [inlined]
 [11] _collect(c::Vector{…}, itr::Base.Generator{…}, ::Base.EltypeUnknown, isz::Base.HasShape{…})
    @ Base ./array.jl:854
 [12] collect_similar(cont::Vector{SubString{…}}, itr::Base.Generator{Vector{…}, HomotopyContinuation.ModelKit.var"#14#18"})
    @ Base ./array.jl:763
 [13] map
    @ ./abstractarray.jl:3286 [inlined]
 [14] sort_key(v::HomotopyContinuation.ModelKit.Variable)
    @ HomotopyContinuation.ModelKit ~/.julia/packages/HomotopyContinuation/Cibx5/src/model_kit/symbolic.jl:19
 [15] _broadcast_getindex_evalf
    @ ./broadcast.jl:709 [inlined]
 [16] _broadcast_getindex
    @ ./broadcast.jl:682 [inlined]
 [17] getindex
    @ ./broadcast.jl:636 [inlined]
 [18] copyto_nonleaf!(dest::Vector{…}, bc::Base.Broadcast.Broadcasted{…}, iter::Base.OneTo{…}, state::Int64, count::Int64)
    @ Base.Broadcast ./broadcast.jl:1098
 [19] copy
    @ ./broadcast.jl:950 [inlined]
 [20] materialize
    @ ./broadcast.jl:903 [inlined]
 [21] sort!(vs::Vector{HomotopyContinuation.ModelKit.Variable}; kwargs::@Kwargs{})
    @ HomotopyContinuation.ModelKit ~/.julia/packages/HomotopyContinuation/Cibx5/src/model_kit/symbolic.jl:27
 [22] sort!
    @ ~/.julia/packages/HomotopyContinuation/Cibx5/src/model_kit/symbolic.jl:27 [inlined]
 [23] _variables(ex::HomotopyContinuation.ModelKit.Expression)
    @ HomotopyContinuation.ModelKit ~/.julia/packages/HomotopyContinuation/Cibx5/src/model_kit/symengine.jl:531
 [24] variables(exprs::Vector{…}; parameters::Vector{…})
    @ HomotopyContinuation.ModelKit ~/.julia/packages/HomotopyContinuation/Cibx5/src/model_kit/symbolic.jl:223
 [25] variables
    @ ~/.julia/packages/HomotopyContinuation/Cibx5/src/model_kit/symbolic.jl:220 [inlined]
 [26] _default_vars_params
    @ ~/.julia/packages/HomotopyContinuation/Cibx5/src/model_kit/symbolic.jl:1042 [inlined]
 [27] #System#83
    @ ~/.julia/packages/HomotopyContinuation/Cibx5/src/model_kit/symbolic.jl:1037 [inlined]
 [28] HomotopyContinuation.ModelKit.System(eqs::Vector{…}, vars::Vector{…}, pars::Vector{…})
    @ HarmonicSteadyState.HC_wrapper ~/.julia/packages/HarmonicSteadyState/iZR0F/src/HC_wrapper.jl:48
 [29] HarmonicSteadyState.HomotopyContinuationProblem(equations::Vector{…}, variables::Vector{…}, parameters::Vector{…}, swept::OrderedCollections.OrderedDict{…}, fixed::OrderedCollections.OrderedDict{…})
    @ HarmonicSteadyState ~/.julia/packages/HarmonicSteadyState/iZR0F/src/Problem.jl:111
 [30] HarmonicSteadyState.HomotopyContinuationProblem(MFeqs::MeanfieldEquations, parameters::Vector{…}, swept::Tuple{…}, fixed::Tuple{…})
    @ QuantumCumulantsExt ~/.julia/packages/HarmonicSteadyState/iZR0F/ext/QuantumCumulantsExt.jl:103