Some heavily indebted mainland Chinese owners have been forced to sell their luxury apartments in Hong Kong at huge losses or discounts, as the economic slump at home takes a toll and a fresh wave of coronavirus makes them question the wisdom of holding on to the assets in the city.At least 10 transactions – nine residential properties and one parking space – have incurred big losses, of up to HK$8.2 million (US$1.06 million), or been sold with steep discounts since the second half of July,…