From my limited knowledge about the Expo router, I think (tabs)/account and /account routes might be interfering because (tabs) is just for grouping, so the URL for both pages will be /account. I am following these docs: Expo Router notation - Expo Documentation
But, I see you have /activities and (tabs)/activities as well. Does that route work?
If you need more help, please share your public repo or a minimal reproducible example. That will let us all work together from the same code to figure out what’s going wrong.