Seand There is a reload that happens about 4.40pm so settings before then may revert but after then they should be stable.
Also any edit to your agile charge windows usually makes all settings revert to the set slots.
Generally I am quite careful to re-check my edits as the last thing I do but I think I've also unexpectedly had my settings revert sometime after 4.40pm so I do wonder if it's possible something else can cause them to reset.