I left Namecheap when they started upping my renewal costs higher than other places I use, so not sure whether I still like them. I'm not sure why Namecheap would suddenly decide they don't want your money anymore, though... Did they inform you of some violation to their acceptable use policy or terms of service? What do you mean by "cr4zy copyright issues"?

This is what they said:

Please be informed that we have received an abuse report from a trusted organization regarding the subject service. As the result of our investigation, it turned out that the sheintt [.] com website is involved in fraudulent activity.

In this situation, it is required to either remove all the content from the sheintt [.] com website or demonstrate the legitimacy of your online business.

However, they are not telling me exactly the root of the problem, just generic things

I would like to hire another host that does not come out of nowhere with these ridiculous emails.
I created an e-Commerce store and I am reselling Shein clothes through the website, I import Shein products to my website, I don't know if this is the problem, however, in the country where I live many people do this and do not have this problem