Is that a full challenge account rather than the free trial time Alan?
I would try to be as consistent with your trade size as possible as otherwise it will likely not get through the account review but a small adjustment weekly shouldn’t be a problem as long as it is not a large reduction or increase in lot size.
Also just because it is at 40% this week doesn’t mean it will keep that trajectory abs it may have a drawdown for example for a week. I would advise being clear what your plan is before starting trading and then sticking to it throughout the challenge personally.
It would be good to see the equity curve also.