About Upwork and jobsuccess - what's the best way to proceed?

Question

Project management

Hello everyone, I need advice on how best to proceed in my situation, and also, if possible, describe the consequences of a negative outcome. By a negative outcome, I mean a return request and / or a bad review.
There is a profile, jobsuccess 87%. I worked on the sly, there are no more active projects.
Prior to this, feedback on all projects is either 5 or no feedback + 1 from 4.85.
A fix-price project is currently in the works, two mailstones have been accepted, the third one is in progress. For the first two money withdrew (well, they were really needed). The client makes the most dissatisfied look, uses the word refund, although he does not explicitly ask for it.
If you're interested in a little more detail:

spoiler

Суть проблемы: осталось пара мелких правок по 3 части работы, клиент на какое-то время пропал.
Вроде на этот период планировали тестовую обкатку приложения, я в общем то и думал что смотрят и пробуют.
Потом внезапно объявляется, начинает сыпать письмами типа "я не доволен как все работает".
На мои вопросы отвечает "АА все плохо".
Через пару дней в письмах к недовольству добавляется просьба о скидке)
Еще через день наконец узнаю чего хочет, попалась пару багов, которые правятся за 5 минут. Остальное хотелки либо не оговоренные ранее, неочевидные, вещи.
Далее пошли рассказы про то, что он почитал про права, возвраты, отзывы и так далее.

Actually I want to understand how it is possible to get out of this situation with the least losses.
I understand that there is a high probability of getting a bad review and jobsuccess falling to the bottom.
Spoon of honey: there is a new client willing to work with me through this exchange.
The project is not big. Several hundred dollars.
If I get a good review for this project (after a bad one) or even a couple, will it even out the situation?
Or is it better to take the client to a new profile and start building again?
I apologize for the confusion. I will be glad for any information.

Answer 1

for a new profile, you will receive an autoban for always on both profiles, whoever
looks at the formula for how zhs is considered and do not ask stupid questions
if the client’s offers are not adequate, you need to complain to the support

Answer 2

learn to negotiate point by point
find out what the client has and how he wants to resolve them
when you have a list then you can negotiate a solution acceptable to both
as long as you behave like an infantile child and well deserve the feedback you are afraid of
if you don't solve your client's problems, someone else will do it at your expense