Can pfq support multiple separate TaylorN?

I'm curious if the hypergeometricfunction input parameter is able to support data in TaylorN format, based on the reported error I guess it's a pfq issue? I am interesting in hypergeometricfunction's Taylor Series,However pFq((2,),(2,),x+y) works but pFq((x,),(2,),x+y) got error.

using HypergeometricFunctions
using TaylorSeries
using LinearAlgebra
x, y = set_variables("x y", order=8)
Base.float(t::HomogeneousPolynomial) = HomogeneousPolynomial(float.(t.coeffs))
Base.float(t::TaylorN) = TaylorN(float.(t.coeffs), t.order)
TaylorSeries.TaylorN{T}(a::S) where {T,S} = (R=promote_type(T,S); TaylorN(R(a), get_order()))
Base.eps(::Type{TaylorN{T}}) where {T} = eps(one(T))
Base.eps(a::TaylorN) = eps(constant_term(a))
pFq((x,),(2,),x+y)

ERROR: MethodError: no method matching iterate(::Type{HypergeometricFunctions.ℕ₀})

Closest candidates are:
iterate(!Matched::Union{LinRange, StepRangeLen})
@ Base range.jl:880
iterate(!Matched::Union{LinRange, StepRangeLen}, !Matched::Integer)
@ Base range.jl:880
iterate(!Matched::T) where T<:Union{Base.KeySet{<:Any, <:Dict}, Base.ValueIterator{<:Dict}}
@ Base dict.jl:698
...
Can anybody help me? Thanks