It's unclear from the question whether the home you already own has a vacation home loan as well.
IE if home A is an investment property, then you can buy home B as a vacation home.
If home A is a vacation home, then you cannot buy home B as a vacation home.
If home A is a vacation home and you're desperate to buy home B as a vacation home, I would think you could refinance home A into a different loan product, and then the vacation home loan would be eligible for that area again. But if you've got a good rate on home A already you may not want to re-finance it at current rates.
@Ryan Moyer good question! None of the properties are vacation homes. I own two duplexes in the city: one has 2 x MTR leases and is on an FHA, the other duplex has 2 x LTR leases and is on a conventional loan.
Given this, it sounds like the 50 mile rule wouldn't apply in this instance. If so, great news. Thank you for calling this out.
Thank you also @Luke Carl for your note regarding the leases!