Increased desats

I'm wondering if anyone has experienced something similar. My little girl was born 17 days ago at 29 weeks and 4 days. She's been breathing independently since day 4 (ventilated at day 1 then weaned off cpap until she was just on air from day 4). She was doing fine, no desats and very few bradys until day 14 where she's started having a lot of desats and needing stimulation to bring her up. This coincided with her feeds being increased to 3 hourly. She's had blood cultures and was started on antibiotics as a precaution but these were fine and had her antibiotics stopped today. Her feeds were put back down to 2 hourly 2 days ago but she's still having these desats. Has anyone been through something similar, where their preemie suddenly started desating out of nowhere?