Leaking mixer tap.
I get lots of calls with regards to taps.
This has been leaking into the vanity and had caused water damage to the base and back of the vanity unit. It wasn’t the tap itself that was leaking. water collecting around the base of the tap had been tracking under the mixer body. I loosened the back screws off, cleaned the base of the tap and vanity top and applied a little sealant to prevent this from continuing.
If you have any concerns, give me a call. Meeting your plumbing needs.