unable to configurate buttons for PTH-651

[fugata]

I tried to use xsetwacom to configurate the buttons for my PTH-651. Here are the stesp I took:

• use xsetwacom --list devices to find the name/ID of my device
• use xsetwacom --list modifiers to confirm that I can use "ctrl" and "shift"
• use xev | grep button to find the name of the buttons
• use xsetwacom --set "Wacom Intuos Pro M Pad pad" button 3 "key ctrl d" to set button 3 to control-D

After I did the above, I opened up an xterm, moved the cursor to the xterm, and then click button 3 --- the xterm then closed, a confirmation that this worked. But I when moved the cursor to the graphics program (xournalpp, in case that matters) and then clicked button 3, nothing happened -- it's supposed to create a new page, and it worked when I issued "ctrl d" from the keyboard instead of the wacom.

I used xsetwacom --get "Wacom Intuos Pro M Pad pad" button 3 to find what button 3 actually did, and I got
key +Control_L +d -d

Is that correct? I also tried
xsetwacom --set "Wacom Intuos Pro M Pad pad" button 8 "key shift ctrl p"
Again button 8 did nothing within the graphics program, and
xsetwacom --get "Wacom Intuos Pro M Pad pad" button 8
returned
key +Shift_L +Control_L +p -p
Is that correct? Is there a way for wacom to send shift and control instead of shift_L and control_L? What are all the +/- signs, and why is there an "-p" and "-d" at the end?

Many thanks!