My daughter has an office plant with a sticky white foam attached to the leaves. I haven't been able to find the answer anywhere.
Certified GKH Gardening Expert
Sounds like a spittle bug problem, though it's usually more watery than sticky. They also do little damage to plants and can normally be hosed off. Here is an article that you may find helpful: https://www.gardeningknowhow.com/plant-problems/pests/insects/spittlebug-control.htm
The stickiness could also be honeydew from another pest - aphids, mealybugs, etc. - in which case neem oil can help, as these pests will quickly reduce the health of the plant. Here is more information: https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm
I would recommend hosing the plant down well and then treating it with neem oil.