Can I have 2 static add to cart buttons on one page?

I have a client that wants to put 2 static add to cart buttons on the same page. I have tried this, but when clicking the 2nd add to cart button, it shows "cart is empty". If I go back to the page and submit the first, I can see both items in the cart.

Is this something that is possible to correct?

It should work. There must be something wrong with the button. I'd have to look at the page to see what is wrong.

I just started to work on this as a test, so you can see the live page at https://run4fundscolorado.com/demo/

the file is also attached. I added some JS (my first attempt at it) on line 212, but have tested the page with and without the JS.

Each add to cart button is taking the shopper to a different cart. It is the second cart page that isn't working, not the add to cart button.

If you update the redirect for the add to cart to go to the cart.php page instead of the shopping-cart.php page I think it will work.