I’ve just installed 5 of these with no issues . As only some seem to be causing an issue I’d change them to a different flow and return . If they still play up swap the wiring in the control box .
Then it’s either faulty actuator ( unlikely to be 3 though ) , faulty wiring box . After that you could just ‘waste’ 50 quid on a different wiring box - just too see what happens ...