I generally like the new scrubby zoom but even with "zoom windows to fit" selected, it does not resize the window when I zoom in.
Which version of PS are you using?
What is the OS?
What is the exact workflow?
Reset Photoshop preferences by pressing and holding Shift+Ctrl+Alt (Windows) or Shift+Option+Command (Mac OS) immediately after you start Photoshop. Click Yes when asked if you want to delete the Adobe Photoshop Settings File. Retry the function that caused the problem.