GCC 8.3.1-3 on Red Hat fails on template class with static function using template parameter

When working with the devtoolset-8 on RedHat 7:

[eftlab@49af022e5a7c git]$ which g++
/opt/rh/devtoolset-8/root/usr/bin/g++
[eftlab@49af022e5a7c git]$ /opt/rh/devtoolset-8/root/usr/bin/g++ --version
g++ (GCC) 8.3.1 20190311 (Red Hat 8.3.1-3)
Copyright (C) 2018 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

[eftlab@49af022e5a7c git]$ 

I've come accross a bug i'd like verified please:

#include <iostream>
#include <functional>

template<class ParentT>
class OpenSession {
public:
  std::function<void()> Run() {
    auto parent    = parent_;

    return [parent](std::function<void()> onSuccess, std::function<void()> onReject) mutable {
      std::function<void()> toRun = [](){};

      RunCallback(parent, toRun);
    };
  }

  void RunCallback(std::function<void()>& toRun) {}

private:
  ParentT* parent_ = nullptr;

  static void RunCallback(ParentT* parent, std::function<void()>& toRun) {}
};


int main(int, const char**) {
  return 0;
}

Compile this with g++ -std=c++17 test.cpp and I get the following error:

test.cpp: In lambda function:
test.cpp:13:32: error: 'this' was not captured for this lambda function
       RunCallback(parent, toRun);
                                ^

It looks to me like in a template class when a lambda capture is checking its arguments it doesn't know that there are references to the template functions in here which leaves me renaming my method as even changing to OpenSession<ParentT>::RunCallback(parent, toRun); the compiler still doesn't see the static function i'm really referring to. Has anybody got any wonderful compiler flags that might tweak this or any other suggestions? Thanks