Kitchen faucet trickling after turning it off

[BobKarr]

Just recently started about a day ago, once I turn off the faucet, water continues to keep trickling out for a few more seconds, rather than immediately stopping.

Here's a clip of what I'm talking about:
I'm thinking it could be a worn out washer or a damaged valve seat? Any advice on how to properly diagnose and check for the root cause?

Much appreciated

 

[Chuck]

Looks normal to me.

Stick a glass under the tap when it is 'off' for a couple of hours to confirm the cartridge is not passing water and dripping continually.

My guess at a root-cause explanation is that when the tap was new the inside of the outlet tube was clean and shiny. This meant that the water inside did not 'wet' the surface and slid out quickly and easily when the valve was shut. As time passes, the inside gradually oxidises and roughens. This means the water will start 'wetting', i.e. sticking to it. Hence, the water forms a film with one surface stationary. The residual water in the film takes a noticeable time to empty because the drainage rate is now viscosity-limited.