I have the same problem with my DD 10mo. One day, out of sudden, she started taking 2 naps 1,5h (instead of 45min) and one 30min, After 2-3 weeks I couldn’t put her asleep at bedtime- because her A time increased, and she wasn’t tired yet. After 3 to 2 transition her naps got shorter again to 45min. After next month she stopped sleeping well at night as well. She already slept for at least 11h in a row and now she wakes up every 10-20 min between 7pm-8.30am and than 2:30am- 5am!!!
It has been like that for a 3 weeks now. And it got worse 4 days ago: her naps are not 45min, but 30-35min!!