Never found a comprehensive list.
The ones I know are:
* Carcosa Seri Negara (Kuala Lumpur, Malaysia)
* Mahakua Hacienda de San Antonio (Colima, Mexico)
* Chateau de Bagnols (Bagnols, France)
* The Strand (Yangon, Myanmar)
* Milton Park (Australia)
AFAIK, most still are hotels, with different management.
What happened each time I guess is that owners expect a better ROI (including refusing to invest more in the property), and/or want their historically significant properties managed by a local company.