Why Your Faucet Drips Only When Another Tap Is On — Diagnosis and Fixes

https://hometriangle.com/blogs/common-plumbing-problems-every-household-encounters-over-time/

That slow, annoying drip that only shows up when someone runs the shower or flushes the toilet is more than a nuisance. It points to pressure dynamics and worn sealing parts that interact under changing flow conditions