None of the original 5 buildings at Telehouse in London have any dishes on the roof but the new Telehouse South a few hundred yards to the South seems to have some on the roof but they don't look like they are for a SpaceX groundstation.

SpaceX groundstations look a bit different, they are a bunch of white domes about 1-2m in diameter, usually 8 or 9 of clustered together.

Here's an example in the UK: https://maps.app.goo.gl/Zy61dfdyp5xrq4w1A

It's handled by Arqiva here in the UK it seems, so no SpaceX branding on anything.

SpaceX also applied for two new grounds station sites in the UK, one a few miles West of Telehouse, south of Rainham. The other site is up in Harlow, Essex.

(I don't think any of this is secret, all of the info above can be found with some googling and scrolling in maps.)