Is it weird that I will stop talking to someone if there’s a greater task at hand?

For context, I’m a Walmart cashier.

Sometimes while in the self-checkout lane, a coworker will chat with me if it isn’t too busy, but as soon as a customer needs help I’ll just walk over and help them (mid-sentence), and then continue the conversation when I’m done. I’m worried that this might come off as rude, as it seems like 80% of people would just continue the conversation to completion or at least a good stopping point before helping the customer.