In Photoshop 2020, I am just stroking pen tool paths with a brush. I don't know where the settings are for the brush that are creating these tapered ends. (see attached image please).

It's not brush settings because I turned that all off, and i tried turning the pressure sensitivity off and on in the brush control panel at the top--- AND I'm doing this on my computer without a pen so I'm not sure why I am seeing any tapering. Thanks!

Un-click "Simulate Pressure". Also, look in the Brush Settings panel (not the controls in the option bar), be sure that under "Shape Dynamics", the Size Jitter control is not set to Pen Pressure, and likewise under "Transfer" that the Opacity Jitter control is not pen pressure.

Could you please post screenshots with the pertinent Panels (Toolbar, Layers, Options Bar, Brush Settings, …) visible to illustrate what you are talking about?

I have the same issue but when I change size jitter to 'Off' instead of 'Pen Pressure' it just automatically changes back to 'Pen Pressure' no matter what I press. I want to paint a mask without the taper on the brush so would prefer not to use paths. Thanks!