A tree philodendron may dry more slowly when its growing conditions become cooler or less bright. The watering routine that worked during active summer growth should be reviewed rather than carried forward automatically.
Check the actual compost, not just the date of the last drink. A large container can remain wet beneath a surface that looks dry.
Look for changes around the pot
Has the plant moved away from a bright opening? Is heating affecting only one side? Has a decorative cover been added? Record those changes before deciding the plant suddenly needs more fertiliser.
Look at the foliage and stems alongside the root conditions. A declining plant needs an investigation; a sound plant growing more slowly may simply require an adjusted routine.
When watering is needed, make sure excess water can escape and does not remain trapped below the inner pot. Check again according to the medium and conditions, without setting a new rigid interval to replace the old one. The useful habit is inspection, especially when the environment is changing, rather than finding one number of days to use for the whole year.
The NC Extension tree-philodendron profile recommends moist, well-drained medium and records root rot in overly damp conditions. That supports checking the root environment rather than using the same interval after light and temperature change.
Related reading: Tree Philodendron Watering: Moisture and Seasonal Changes.