This critical update addresses an issue opening hyperlinks in
formula fields. If you have formula fields that contain a HYPERLINK function, Lightning Experience currently ignores the target value when
attempting to open the link. This critical update ensures that the target value for hyperlinks
is honored, whether it's explicitly configured or set by default. This critical update is
automatically enabled in Summer ’19 on May 17, 2019.
Where: This change applies to Lightning Experience and the Salesforce app in all
How: From Setup, enter Critical Updates in the Quick Find box.
Then select Critical Updates. For Lightning Experience Honors Target
Values for Hyperlinks in Formula Fields, click Acknowledge.