fix: remove early exit in late_binding_update_u0_p when u0 === missing

Author: AayushSabharwal

src/systems/nonlinear/initializesystem.jl

@@ -588,19 +588,22 @@ end
 function SciMLBase.late_binding_update_u0_p(
         prob, sys::AbstractSystem, u0, p, t0, newu0, newp)
     supports_initialization(sys) || return newu0, newp
-    u0 === missing && return newu0, (p === missing ? copy(newp) : newp)
     # If the user passes `p` to `remake` but not `u0` and `u0` isn't empty,
     # and if the system supports initialization (so it has initial parameters),
     # and if the initialization solves for `u0`,
     # THEN copy the values of `Initial`s to `newu0`.
-    if u0 === missing && newu0 !== nothing && p !== missing && supports_initialization(sys) && prob.f.initialization_data !== nothing && prob.f.initialization_data.initializeprobmap !== nothing
-        if ArrayInterface.ismutable(newu0)
-            copyto!(newu0, getu(sys, Initial.(unknowns(sys)))(newp))
-        else
-            T = StaticArrays.similar_type(newu0)
-            newu0 = T(getu(sys, Initial.(unknowns(sys)))(newp))
+    if u0 === missing
+        if newu0 !== nothing && p !== missing && supports_initialization(sys) && prob.f.initialization_data !== nothing && prob.f.initialization_data.initializeprobmap !== nothing
+            if ArrayInterface.ismutable(newu0)
+                copyto!(newu0, getu(sys, Initial.(unknowns(sys)))(newp))
+            else
+                T = StaticArrays.similar_type(newu0)
+                newu0 = T(getu(sys, Initial.(unknowns(sys)))(newp))
+            end
         end
+        return newu0, newp
     end
+
     # non-symbolic u0 updates initials...
     if !(eltype(u0) <: Pair)
         # if `p` is not provided or is symbolic