More sessions can produce more orders while the customer journey becomes less effective. Looking only at total revenue can hide falling conversion quality, weaker intent or a mobile experience that loses the marginal visitor.
Decompose the change
Separate revenue into traffic, conversion rate and order value, then segment by device, source, market and new versus returning visitor. An aggregate number can combine several opposing movements.
Compare like with like
A campaign that brings colder demand should not be judged against brand search without context. Compare landing pages, audience intent and acquisition cost, then check whether the experience answers the questions each segment arrives with.
Inspect the path, not only the endpoint
Product discovery, product detail engagement, cart creation, checkout start and payment completion show where intent is being lost. Qualitative review helps explain why the step changed.
The decision to make next
Choose the highest-value leak, define the behaviour that should change and test the message or experience before buying more of the same traffic.