Please share your site url i will check and let you know.
Hello! I have the same problem. Sometimes I get a message "There was an error while updating your cart. Please try again." when I try to add products to the cart.
And also this message is written to me if I want to remove products from the cart.
Im no expert, just a user, what is the messenging app you have on your website? if it is the fb messenger one then perhaps that is the issue, thats what it was for me. I have sent them feedback, and responded to their "sorry to see you go" email, but as yet no response from them. I used shopify live chat support to help me, Dave was amazing and helped me locate and resolve the problem really quickly