It’s not like these drones would uncover much more than can already be seen by satellites. Probably much more valuable letting them be, studying their physical characteristics, flight behavior, and RF use. Also easier to track down the source - they’ve got to land at some point.
These US bases should be closed, I don't care they are for mutual training between both countries or other such excuses. The UK should be as hostile to US made weapons and NATO in general as much as the French.