Hi! Welcome to the Samsung Members community.
Check your phone's settings to ensure WhatsApp has permission to access your contacts. Go to your phone settings, then navigate to Apps > WhatsApp > Permissions and make sure "Contacts" is toggled to "Allow."
Ensure "Contacts" is enabled in your account sync settings.
Go to "Settings" > "Apps." Find "WhatsApp" in the list. Tap "Permissions." Ensure "Contacts" is "Allowed."
Go to the contacts list within the regular contacts app, click the three dots, then select "Settings" > "Sync contact accounts"—make sure your Gmail account is listed.
Restart your phone.
If none of the above work it may be worth speaking to WhatsApp support
