If you think you have problems in WordPress and you don’t know how to solve it, you need to
- Point out any mistakes that previous developers do. It is like the brainstorming phase.
- Solve the mistakes.
To do it, you can outsource it. Outsource several freelancers from Fiverr WordPress Error section for point no. 1. They may come up with several same mistakes, but hire several people, you can know any mistakes. I suggest you hire 2–3 people. Use low-price and high-price service. You can save money but you will get several recommendations. If possible do not give any login.
After that, you need to solve it. Again, outsource from Fiverr. You can use the same freelancer as the first phase or the new one. At this phase, you may need to give login, so choose the trustworthy freelancer. So, you may prefer a pro verified freelancer of Fiverr.