Yeah its going always takes a few weeks for news to become digested and show up in the polling. Always longer than the newsies and wonks think it should; 3-6 weeks some times.
20% of Republicans in the primaries were still voting for Nikki Haley, likely as a protest vote, even long-after Nikki dropped out.
So this is all within expectations. As usual, the Trump delusional refuses to accept reality. Its up to the rest of the country to band together and vote against him.
If Mr Trump eventually can't run, Ms Haley is the presumptive candidate, having won a primary somewhere. And it's too soon to launch another bid by anyone else.