Record matching issues between Salesforce and Sales Navigator, are generally caused due to step being missed during embedded profile installation, or due to individual’s edit permissions in Salesforce.
Here's a tip
With Record Match Correction for CRM integrations, you can also verify and correct a CRM record match by clicking Edit match on an Enterprise profile, then View in CRM to confirm/create a new CRM match record.
During Embedded Profiles installation, there is an additional step to drag down the LIMemberToken and LICompanyID fields into the top area for Leads, Contacts, Accounts, and Opportunities. This information can be located in the installation guide on page 8.
Additionally, for Accounts and Opportunities, there will only be one field available, the LICompanyID Field.
To confirm that you have edit permissions in your organization’s instance of Salesforce, please reach out directly to your Salesforce admin.