It's now a button underneath the Preview Window along with a '3 dots' link which includes 'Edit Visible Button Set' which allows you to choose other control buttons that you may wish to appear under the Preview Window.
Just upgraded to 21 and, sadly, this isn't working for me (wanting it to resume from location paused/stopped vs started from (keeps going back to where I started playing from). Checking/unchecking the button does nothing.
@sonicvision ... It's definitely working as expected for me in VP21b315. Perhaps try resetting VP21 back to its default settings as doing this often clears up odd behaviours.
If you haven't done so, edit the visible button set so the "Play/Pause or Play/Stop" button shows on the transport bar along with the play and stop buttons. When you click on the "Play/Pause or Play\Stop" button, the button icon will turn to a blue background when it's in the Pause mode. This way you will have a visible indication showing the mode it's in. There's another way by toggling a menu item, but you can't tell if it's selected or not.
Once you have the "Play/Pause or Play/Stop" button in the mode you want, you can hide the button by going back into the "edit visible button set" and deselect it.