Open Radar

 
In Mac Catalyst apps, mouse clicks are ignored while scrolling (with a scroll wheel). For trackpad scrolling, clicks are registered correctly. 

Steps to reproduce:
1) Preparation:
  1.1) Open a Mac Catalyst app, for example Podcasts
  1.2) In the sidebar, select Top Charts
  1.3) Scroll down the list to preload around 200 podcasts.
2) Reproduction:
  2.1) Using a trackpad, get the list scrolling (with two-finger flick gesture)
  2.2) Press the trackpad. Observe: inertial scrolling stops and the app registers the click (opens whatever podcast is under the cursor)
  2.3) Now, get the list scrolling using a scroll wheel (such as free-spin mode on Logitech mouse)
  2.4) While scrolling, press the left button of the mouse.

Expected result:
The scrolling stops, the click is registered (like with the trackpad)

Observed result:
Scrolling continues, the click is ignored.

Additional info: 
In non-Catalyst apps (such as Mail), the issue does not reproduce: both mouse and trackpad stop scrolling and register the click.