MacBookPro: Click not being actioned unless one finger touching

[sqeeezy]

I use my trackpad right-handed, clicking with my thumb and leaving it always in the lower third of the pad. I've set EdgeBottomSize to 20 to ignore thumb touches, which works fine. I've set ClickFinger0 to 1, rebooted, but I still have to keep one finger touching after moving the cursor, while I click the physical button with my thumb. If I don't have one finger touching the click is not registered. If I have two fingers touching when I click it generates a right-click, as expected.
Option "ClickFinger0" "1"
Option "ClickFinger1" "1"
Option "ClickFinger2" "3"
Option "ClickFinger3" "2"
Option "ButtonMoveEmulate" "false"
Option "ButtonIntegrated" "true"

terminal output shows ClickFinger0 option not being read:
me@here:- sudo cat /var/log/Xorg.*.log | grep ClickFinger
[ 5.013] () Option "ClickFinger1" "1"
[ 5.013] () Option "ClickFinger2" "3"
[ 5.013] () Option "ClickFinger3" "2"
[ 5.068] () Option "ClickFinger1" "1"
[ 5.068] () Option "ClickFinger2" "3"
[ 5.068] () Option "ClickFinger3" "2"

[EDIT] had previously installed via xbps. Reinstalled from git and built and now ClickFinger0 behaviour as expected.