You're stripping off the read-your-write identifier during the redirect. As a result, you have a race condition and are relying on the cookie association to complete before the second page loads (which is far from guaranteed). It will work in most cases, but with the aliId it will work in all cases.
Please read this blog post: Don't call a Marketo LP an “External URL” even if it sort-of-works
You have to capture the aliId that you're now deleting and make sure it ends up on the second page's URL -- I gave related pointers in the blog post.
The read-your-write cache is what I meant by "cosmetic" -- it doesn't actually wait for the data to save, but allows you to "decorate" the second form as if it's been saved.