World Builder Not Always Updating Area Dimensions

When I drag an area to resize its dimensions, there's something weird about it. It's not always saving. Maybe I'm missing a flow step? Anyway, here's a video with me vainly trying to resize a river area and it keeps resetting itself. It's a little weird... sorry for the video length but something isn't right. See video here: https://discord.com/channels/1087479995083018372/1092257107300069557/1222038298801999893