What should be done:
You can agree with your taiwan whatsapp opponent, but it is better to ignore his words and not pay attention. Continue negotiations as if everything is going according to plan.
The one who knows how to listen and ask questions correctly controls the conversation. You should not burden your opponent with a presentation of yourself and your position from the very beginning. First, ask questions about the needs of the other party and clarify what criteria they used when choosing.

Once you have identified the needs precisely, you have the opportunity to provide your opponent with exactly what he is looking for.
Download a useful document on the topic:
Checklist: How to Achieve Your Goals in Negotiations with Clients
6 Common Mistakes in Business Negotiations
To fall into despair when something does not go according to plan
Both parties prepare for business negotiations. There is a chance that their plans will not coincide, and the conversation will go in a completely different direction. When preparing for a meeting, you should consider several possible scenarios. This will give you confidence and help you achieve your goal.
Don't take emotions into account
Business negotiations are not conducted by robots, but by living people. Of course, they are interested in statistical data, logical conclusions, and in-depth analysis. At the same time, they also have purely human aspects. The language of business negotiations should be moderately emotional and lively. Otherwise, everything boils down to a boring exchange of information.
Turning business negotiations into a presentation with a huge budget
To clearly present your position, it is better to use regular charts and diagrams. Spending large sums of money on creating an expensive presentation may be in vain.
Rely on the ability to improvise
The ability to quickly find a solution and improvise is a very valuable quality. However, you should not rely solely on it in the process of business negotiations. The other side may conclude that you have a poor understanding of the issue under discussion. And who needs an incompetent partner?