Update abstractodesystem.jl

Author: ValentinKaisermayer

src/systems/diffeqs/abstractodesystem.jl

@@ -573,11 +573,11 @@ function process_DEProblem(constructor, sys::AbstractODESystem,u0map,parammap;
 
     pdefs = mergedefaults(defs, parammap, ps)
     u0defs = mergedefaults(defs, u0map, dvs)
-    du0defs = mergedefaults(defs, du0map, dvs)
 
     u0 = varmap_to_vars(u0map, dvs; defaults=u0defs)
     if implicit_dae && du0map !== nothing
         ddvs = map(Differential(iv), dvs)
+        du0defs = mergedefaults(defs, du0map, ddvs)
         du0 = varmap_to_vars(du0map, ddvs; defaults=du0defs, toterm=identity)
     else
         du0 = nothing