The market is saturated with STR's further from the beach and attractions, so my advice is to be picky about your location and underwrite the numbers carefully to make sure the investment will be profitable. 

They are cash flow positive and have over 1B in assets ( net is close to 350million ) I’m only thinking that the seller wanted to make it attractive to sell his building having no renewal option which can give some leverage to new owner.

Think lakefront properties in small towns, destinations with new attractions (casinos, amusement parks)...Another idea is investing in properties suitable for accessory dwelling units to create dual-income setups, especially in cities with relaxed ADU regulations.

A steady annual growth rate, diverse industries, and affordable living attract residents.

Spanaway, DuPont, and Yelm are areas I'd consider if you want to attract those working in Tacoma/Olympia and living further out as well.The new fast ferry from Bremerton and Kingston is making the peninsula a more viable option.

A $200,000 duplex might have identical rents in municipality “A” and municipality “B” but the property tax rates will vary, local regulations will dictate licensing requirements, labor rates will vary & the particular location will dictate insurance premiums since insurance carriers will weigh local replacement costs and whether the municipality is viewed as being a “plaintiff friendly” in arriving at insurance premiums.Better situated assets will attract better tenants.

Could there be something I’m not aware of that’s keeping other buyers away despite the attractive pricing?

With platforms like Airbnb or Hipcamp, you can attract travelers looking for unique stays.

A good property manager can guide you in selecting properties that will attract a tenant segment with a high concentration of reliable people.Access to cost-effective resources for renovation and repairs.Lease terms enforcement.

All said, drop the rate to market or slightly below (if you're in a tougher market) to attract a quality tenant, then pursue the refinance or sale as some have suggested already.