I guess your trackpad is a clickpad, iow it does not have separate physical buttons,
but you click the bottom right / left of the pad down to click, correct?
In that case GNOME3 now defaults to clicking the pad anywhere with 2 fingers
at the same time to do a right click.
Ah! That's it. I must have missed that in the GNOME3 release notes.
If you want the old bottom right area is a right click behavior, install
gnome-tweaks, run it and go to: "Keyboard and Mouse" and then for
"Mouse Click Emulation" select "Area".
I will definitely do that. Thanks, Hans!
I confirm that both the two-finger click and using tweaks work.