Agree with AndyR, Grays of Westminster are a Nikon specialist and should be able to clarify any points and advise what is/isn’t working ‘normally’. Only older Nikkor lenses had an aperture ring on the lens barrel. YouTube is another rich source of info for many camera specific topics.
I’m no longer a Nikon user so, my comments below are based on what I can remember. There were several series of f-mount Nikkor lenses, AI, AIS which permitted manual control and used a registration pin (or ring) to inform the camera body what aperture had been set. The last series of lenses to retain an aperture ring typically had to be set at f22 (smallest aperture) on lens so that camera body could control and set the desired aperture – even in manual ‘M’ mode. You won’t see the aperture blades close down until the moment you trip the shutter. The newest f mount lenses don’t have any aperture ring on the lens barrel at all. Aperture is always set via the camera body, whether using modes ‘M’ manual, ‘A’ aperture priority, ‘P’ program or ‘S’ shutter priority.
Some newer film camera bodies (possibly f801) can’t quite remember now, can’t use older manual lenses, with the aperture set on lens ring as they lack the mechanical interface to detect an aperture set on lens – so won’t ever stop down. These had always to be set to f22 (smallest aperture) and then aperture was controlled via camera body – even in ‘M’ mode. The last ‘top of range’ film bodies (F5 and F6) still permitted older lenses to control aperture either via a body dial or the lens aperture ring because they also retained a mechanical indexing ring. Hope this helps.