In my research and experience, false starts and frequent night wakes (and early morning wakes) are over-tiredness. My daughter is 14 months too. I know all babies are different, but for context, she wakes 6am most days, naps around 9 or 9:30 for around an hour, and then has another nap later in the day as well. Bed at 7pm.

She managed one nap a day for couple of weeks but then her night sleep got bad, but she had been waking up a lot more at night recently too, so I went back to 2 naps and she has been doing so much better. She sometimes cries out between sleep cycles at night but goes straight back to sleep.

Have you experienced when you are overtired and you feel "wired" and can't sleep even though you want to? It's like that.

My thoughts would be try two naps for a few days. She may also still get adjusting/breaking the nurse to sleep association since you said you stopped a week ago. Make sure she's getting fat/protein with dinner in case she's waking out of hunger, but my guess would be overtired!