Arrived onsite to customer request to install caulking in a couple missing places. Customer also noticed then when tub spout was running shower head would also come on. After a long diagnostic process found that base pex 90 was the issue and was restricting flow enough to pressure up Shower line. Replaced and supported new fittings and tested new installation. No leaks present. Thanked customer for her patience and for bringing the issue to our attention. Tub and shower is now properly functioning. No charge as work was under warranty