We found a curious font display issue, which can only be reproduced if the "new zoom" feature flag is active:

• We can reproduce it with build 20026.20076 with the zoom slider visible (e.g. in the "Current Channel (Preview)"), but
• we cannot reproduce it on the same build with the zoom slider invisible (e.g. on a freshly updated system in the Current Channel, which has not received the staged rollout yet) or with older builds (e.g. the current Monthly Channel build).

The problem itself is unrelated to zooming.

Repro

1. Create a new Access database.

2. Create a new form in Design View.

3. Add a Tab Control.

4. Set the tab control's "Use Theme" property to "No".

5. Add a button with the following code:

Private Sub Command3_Click()
    Dim start As Double

    ' Localize the page name, if you use a non-English version of Access
    Me.Page2.Visible = True

    ' Simulate long-running operation (3 seconds)
    start = Timer
    Do Until Timer > start + 3: Loop
End Sub

6. Save and open the form in Form View.

7. Click the button.

Expected result: Nothing happens for 3 seconds.

Actual result: The tab header's font switches to some old raster system font (MS Sans Serif?). After 3 seconds, the form returns to the 21st century.

This issue is easy to work around: just do the long-running operation before setting the Visibility property, this will reduce the font-change to a short flicker.

Still, this appears to be an unintended side effect of the changes made for the "new zoom" feature, so I thought it might be helpful to report it while that feature is still being worked on.