The US Ospreys will be training flights usually in company of MC130J Commando II ( the J Herc version of the combat Talon) both are from the the 352 Special Operations Wing out of Mildenhall
The RAF are taking advantage or reduced civilian traffic to run training and familiarity flights around the UK civilian airports.
Try one of the flight radar apps, or web sites such as
adsbexhange but not Flightglightradar24 as that rarely shows military aircraft.
Also keep an eye on
this thread in Parc Ferme as there has been talk of recent military aircraft activity there as well.