And a Merry CHRISTmas to you, too, Tom!
Pictures are good.
With this being outside, any idea what is causing the staining?
The term sealer is very misleading. It should be called “temporary stain blocker while you quick clean it up”. It does not stop moisture. Especially in physical cracks. But realize that the waterproofing should have been done before a single piece of stone was installed. It’s the subsurface waterproofing that keeps the moisture from penetrating into the structure. Do you have any idea of how the waterproofing was done? We might be able to see something with a few pics.