MTK - structurally singular initialization?

Specific Domains Modelling & Simulations
1

I have a somewhat complex model constructed from my own components. Doing mtkcompile produces a system with 18 unknowns and 18 equations: 14 DEs and 4 AEs.

When I create the ODEProblem, I am told:

Warning: The initialization system is structurally singular. Guess values may significantly affect the initial values of the ODE. The problematic variables are SymbolicUtils.BasicSymbolicImpl.var"typeof(BasicSymbolicImpl)"{SymReal}[intake₊b₊pˍt(t)].
│ 
│ Note that the identification of problematic variables is a best-effort heuristic

Yet, the initialization seems to work:

ODEProblem with uType Vector{Float64} and tType Float64. In-place: true
Initialization status: FULLY_DETERMINED
Non-trivial mass matrix: true
timespan: (0.0, 50.0)
u0: 18-element Vector{Float64}:
      1.0
      1.0e-6
      0.0
      0.0
      0.0
      1.0e-6
      2.30782125e6
      0.0
      0.0
 100000.0
      1.0e-6
  39023.93516845321
      0.0
      1.0e-6
 199391.5
      0.0
      1.0e-6
      0.0

When I try to solve the problem using Rodas5P, there is a solution, and the solution makes sense.

Question: How can I figure out why there is a report about “singular initialization problem”? And what do I need to do to fix/get rid of this warning?