Links in email no longer open a new window

I'm running Sequoia 15.0.1, and Safari 18.0.1 on my Mac Mini M1. I use Gmail and Kiwi for Gmail 4.2.7 is my email client. I've always been able to click a link in a email and have it open in a new window. Now, when I click the link it opens in a browser window, but I have to manually switch to the Safari window to see the linked content. What has changed and how can I get back to having the link open in a new window?