Integration connections can have two possible status values: OK or Invalid.
If your integration status is OK, the integration connection is working normally.
If your integration status is Invalid, something is wrong and the connection is not working as it should.
The "status_reason" indicates what is the problem with the connection.
NOTE: The "status_reason" is visible on the reconnect page. If your integration says "disconnected" click the blue "reconnect" on the right side to see the details and status codes in order to repair the connection. Please notice, you need to be an admin user in Pipedrive and Leadfeeder to fix connection issues.
You can see the status of your integration via your Leadfeeder Settings by going to the tab Account and clicking the name of the in integration on the left side of the view.

Here's a list of the known values for status_reason, a description of the error, and how can it be fixed:
Pipedrive
account_not_open
The Pipedrive company is not active. Remove the integration and connect a new Pipedrive company.
company_id_mismatch
The API token is from a different Pipedrive company. Change the API token or remove the integration to connect a new Pipedrive company.
invalid_access_token
The connection between Pipedrive and Leadfeeder has failed. Reconnect to Pipedrive from your account's Leadfeeder Settings.
invalid_api_token
The API token entered is not valid. Reconnect to Pipedrive.
not_admin
The user who did the connection with Pipedrive is not an admin in Pipedrive anymore. Reconnect with a Pipedrive admin user instead.
token_refresh
The connection between Pipedrive and Leadfeeder has failed. Reconnect to Pipedrive from your account’s Leadfeeder Settings.