Hello there,
I'm a plant owner with really no experience in philodendrons, but I got this plant as a gift around 9 months ago. She was doing good for quite a while, hanging in front of a northeastern facing window. However, I recently repotted her because of damage to the old pot, and I've been noticing some signs of distress. When I repotted her I saw that while there were no signs of rot, the existing root system was a bit underdeveloped and small, not as extensive as I would have expected for a plant of this size. Some new growth has been doing really well, but some stems are a bit worrying in how they were initially cut and a few older leaves are beginning to wilt or tint yellow. A few had started to wrinkle, something I wasn't sure was due to the cold weather or from over/under watering, something Ive been somewhat recently anxious about with this plant. For the moment I watered and misted her and moved her to a sunnier place to see if that would help. Any help from someone who has more experience with these plants would be amazing, thank you so, so much!