Version: 0.B-2607 but present for at least a month to my notice.
I thought it had been fixed a long time ago but recent sorting since the piles-of-items-don’t-lag-much edit by Kevin, I’m back to using this sort function and rediscovered the issue.
Advanced itemsorting via / key reveals that [1][2][3] are in fact mapped to keys 789.
Likewise, [7][8][9] are mapped to keys 123.
456 are mapped correctly.
This error does not break the game but when selecting which tile to move items to, I invariably get things reversed.