The problem with Wechat is a known globally issue.
They tightened their security policies especially after the trade war between China and USA.
Having WhatsApp on your phone doesn’t stop you from using wechat. They just upgraded lots of their security policies just the way getting a visa to America has been tightened, so it’s not really about WhatsApp.

Few tips on creating account:

1. Use a unique name.
If you keep using different sim cards but same name, chances are that they will keep blocking it. Use something like your native names, trying to create account with Olorunshola Emmanuel now chances are that it’ll be blocked because I’m already verified so any new user will be seen as a scam or impersonating.

2. Try and sign up when you have a very strong network. At times when they notice you’re going on and off during registration, they flag the account.

3. Immediately you’re able to sign up and you open, ensure to send a friend request to someone already using the app, either me or any of my admins. To add the person, add them directly from phone contact, if the person accepts and chat with you immediately, I think your chances of getting blocked will be slim.

4. Immediately upload your profile picture and also update your profile with your full name, email etc.
Email works especially if they block you, you can easily retrieve your account using the email.

5. Before creating a new account if you have been blocked before, go to phone settings, apps, select wechat, scroll to storage, select clear cached files and clear app data also. Then start afresh using a new number and unique name.

This are just my assumptions, I don’t have any official backup to explain this things in case they still don’t give you result but it stand a very good chance.
Hope this helps, good luck.