Will the Connector be impacted after changing Jira Instance URL?
Atlassian has recently released the Cloud Site Rename feature which allows changing the Jira instance URL.
More details are available in the following documentation, and Atlassian recommends checking the apps from the top vendors in the Atlassian Marketplace to find out if they're compatible with instance URL changes and if so, how that may affect your installed app.
Per this list, Connector for Salesforce & Jira is compatible with the Cloud Site Rename feature. Furthermore, as per our tests, changing the Jira instance URL does not have any impact on the connector, however, you will need to reauthorize the connection to ensure the connection between Jira and Salesforce continues to work.
Here's how to reauthorize the connection:
Log into your Jira.
In Jira > Salesforce > Connections > locate your connection > click Revoke Access then click Revoke to confirm.
Select the environment type of your Salesforce instance, either Production or Sandbox.
Then click Authorize to authorize the connection.
If you're not logged into Salesforce, the browser will load a new page and prompt you to enter your Salesforce credentials.
If the authorization was successful, the Status will change to Authorized.
After the connection is successfully authorized in Jira, follow the steps in this page to update the API Access Token in Salesforce.