So, her WU time has moved up by an hour. Have you moved her naptime up too, or was it always around 1? If so, that might be what's going on, she's waking up later and isn't ready for the nap then.
Also, with the 18 mo SR, it's perfectly normal for LOs to take a long time to fall asleep in the day and in the evening. Even my sleep-loving LO1 did this, and we just had to ride it out. There was no fix, I'm sorry to say! If you can find a way for her to go to bed in a gentle manner, so that she'll stay there happily enough, even talking to herself, that would probably be the way to go.
Just to clarify on naps though: has she ever done a regular 2 hour nap during the day? As you say, her nights are looking good, for now, so I wouldn't panic.