I can't change a working order's price

No Update button. It appears only after you change the price in the chip. A market order has no price to step. An order sent by an older version of Tented shows its price but cannot be changed here; change it in TWS.

“The order price was not changed”. IB or TWS refused the change, or the order is no longer working. The toast carries IB’s reason.

A price I changed in TWS is not shown. By design: Tented does not read TWS-side price edits back.