Logged out from Pocket D with Walk mode turned on - on returning some hours later, found that I could not turn it back off.
Restarted client, re-verified.
Despite having logged out this time in my SG Base, relogged in medical area of Pocket D again.
Swapped Walk with an ability on toolbar #1 so I could use my keyboard to switch it - walk mode disabled at last.
I know I found a fix, but thought it definitely worth mentioning.