DISCLAIMER: Although I am a lawyer, I am not yet licensed to practice law in California. The following is not legal advice and is not intended to create any attorney-client relationship. For actual legal advice, please see a real-estate lawyer licensed to practice in California.

Under general principles, your title company is correct. Once there is a sale or a refinance, the mortgage that precedes (and therefore has priority over) the easement will be extinguished and all future takers by grant or mortgage will take subject to the easement.

Thus, I would see no issues w/r/t the servient tenement. However, I would not be too happy if I had the dominant tenement because if the mortgage at issue ever forecloses then arguably the easement would be extinguished. I say “arguably” because it depends on multiple factors, not all of which I can be sure I remember off the top of my head.