Q.Is the yellowing of the tips of leaves of palm trees normal?
Is it due to overwatering? Under watering ? Can I treat those browning tips on my palm tree with scissors ?

Certified GKH Gardening Expert
No, it's not normal. You may want to get a soil test to see if it is due to a nutritional problem. It also could be improper watering. Palms need a deep watering about once a week and allowed to dry in between waterings. Palms should be fertilizied about three times a year with a fertilizer for palms.
In the meantime, you can trim of the edges to improve its appearance.
https://www.gardeningknowhow.com/ornamental/trees/palms-trees/how-to-fertilize-palm-trees.htm