Guided mode stuck on weighing step without anyway to reset it

It requires 3 seconds of maintaining the same weight, but I fucked up and initially pressed too hard initially, so now it's constantly stuck.
The only solution is to reset the app

Start by reproducing the guided mode weighing step and inspect how the app tracks the three-second stable-weight state. Add a way to reset that state without restarting the app, then verify that a mistaken initial weight can be cleared and weighing can begin again.

Written by the indexing model from the issue text.