Sometimes "Continue Shopping" goes back to checkout

My setup: ZenCart 1.54
Responsive Sheffield Blue 2.0
Events Manager
Plus so many others the list would be too long.

I am having a problem with my "Continue Shopping" button. Is it suppose to act like a javascript back button?

It normally just brings you back to the product listing page you were on before clicking the "Add to Cart" Button. That's fine I guess. I would rather see it go to the category page instead. ( Can this be done )?

However that is not my main problem. Let's say that you proceed to checkout and then decide to go back to the shopping cart page, what happens is that the "Continue Shopping" button link takes you back to the checkout page rather than to the product listing page, in other words it seems to act like a javascript back button. Is this normal functionality? If so it is very confusing to the customer.

Also every once in a while the "Continue Shopping" button goes to my events calendar for no reason what so ever. ????????

I don't see any error logs being produced.

Can someone offer some suggestion?

Thanks

Frank

Some of the "back" buttons or "continue shopping" buttons actually trigger a javascript call to go "back" just like the browser's "back" button.
Sometimes however they are built by specifying the URL of the last page in the store's "navigation history" for that user. This is triggered by the calls to $_SESSION['navigation']->set_snapshot() or add_current_page(). These are used to remember where the customer was last doing something that perhaps required a temporary redirect such as to log in. Consider the case of commencing checkout: click a product, click add-to-cart, click Checkout. It snapshots that they were trying to go to checkout, then takes them to Login so they can have their account data available, and then after login it returns them to the intended checkout page.
Some of the "back" or "continue" buttons intentionally use this same functionality to take people back to what they last requested the store to do.

Sometimes when people alter the normal flow of various pages they inadvertently remove some of the default nav behavior and then get some unexpected results. Similar when they add extra snapshots by mangling the checkout flow between pages.

Perhaps that can give you insight into exploring what's been changed on your own site.