Hey Jen,
We had something similiar with R around this age so yes I do think there's a developmental thing at play. Equally I think your nap is contributing to your short nights.
Ruby was down to one hour at 2pm at this age. We tried dropping the nap very recently due to numerous NW and EW. It was bit a good move for her. She ended up an OT mess. Although OT is inevitable with this nap transition as with any other, she was beyond it so we've gone back to napping (45mins at 2pm). She's a bear on WU but it's better than her being that way all day long. A cross to Bernie think when cutting the nap under one hour.
So what to do? Iiwm I would cut the nap to an hour and bring BT forward. So something like:
WU: 7.15-8am
Nap: 2-3pm
BT; 8pm
What do you think?
Hena