Funny timing on this because my sister had the exact opposite thing happen at her climbing gym in Denver. Their auto belay system kept giving her the green light all through December, then one day in February it started locking up and refusing to let her climb. Turns out the camera kept mistaking her chalk bag for a loose harness strap. She spent like 20 minutes arguing with a machine that doesn't even have a speaker. The staff just shrugged and said the update would fix it eventually. So yeah, these systems swing back and forth like a bad mood.

Locking the cells isn't the fix people think it is. When willow407 says it's a total game changer, that only works if everyone agrees on the labels first. Lock a cell with free text in it and you just froze the mess in place. The real problem in the original post was the drifting categories, not people typing over totals. A locked template with fixed labels like produce and bulk solves it because the options are limited, not because the cells are protected. Locking is the last step, not the first one.