JsonElement is very impractical at this point

[KevinKrueger]

Change this:

private static TUISchedule CombineTuiSchedule(TUISchedule schedule,  JsonElement changes)
{
    var c = JsonSerializer.Deserialize<TUISchedule>(changes.ToString());
    CopyValues(schedule, c);
    return schedule;
}

to this:

private static TUISchedule CombineTuiSchedule(TUISchedule schedule, TUISchedule changes)
{
    CopyValues(schedule, changes);
    return schedule;
}