In December 2018 it was reported that the bank was trying to reduce its exposure to the project. Either by selling the whole thing and then leasing back part of it, or selling part of it and retaining one of the two buildings.
see
here
The major partner was an Indonesian property company. Knowing the way things work in Vietnam and Indonesia, probably neither party was honest with the other. The Singaporeans pulled out, that says a lot. As fast as Vietnam is growing, it looks like the bank bit off more than they could chew.