Trade completed after TNF, how do i handle this?

Sleeper league app. Today, after TNF completed a user traded:

London
Tee Higgins
FAAB

For

GIbbs

I don’t think i changed any sleeper settings so the trade was processed. But now the guy who traded London, got the London points and gets to start gibbs for sunday. I know it’s a different position, but is it fair?

If not, what settings need to be changed to fix this? (First time commish) thank you!