The created groups on the Huawei smartphone can be deleted at any time, leaving the stored contacts, only the group is deleted.

Android 10 | EMUI 10.0
Delete group -  Open the  Contacts app
Delete group -  Tap on  Groups
Delete group -  Choose a  group
Delete group -  Tap on  More
Delete group -  Tap on  Delete group
Delete group -  Confirm with  Delete
  1. Open the Contacts app
  2. Tap on Groups
  3. Choose a group
  4. Tap on More
  5. Tap on Delete group
  6. Confirm with Delete

Huawei Instructions