I’m getting the same error and have worked with my host and Printful.
They each say it is the other.
I’m on Hostmonster, which I think might be the same as Bluehost.
Product was not added!
Failed! The request couldn’t process fast enough, please increase the maximum execution time on your server. If that doesn’t help, check your server error logs.
That’s all we know. If you need some help, please contact our support, provide the error code below, and we’ll see what we can do.
CODE: G453911284