Not common with me, but then I've not got big manly pipe work running such a height. I'm sure a lot depends on the tank level. look at it at two extremes ...
Imagine if the tank were completely full, the pump would just be circulating fluid. When it stops the flow round the circuit simply ceases and there's no back flow.
With a few mm in the bottom of the tank, you have quite a volume due to 2" pipe work (I bet you'd be surprised how much it is if you work it out) and head due to the height of the pipe, wanting to rush back into the tank. I'm sure the small bore of the sight tube isn't helping ... I use 22mm acrylic on a much smaller set-up.
I've had a similar thing on a piping system on a ship. We had a pump in the engine room pumping sea water up to above main deck level (big tanker, so long pipe) and a non return valve just after the pump. Pipe work would have been around 10". Idea being as soon as the pump started flow should be available at the top level. What happened in practice was that when the pump stopped water tried to fall back down the pipe and the NRV slammed shut with such a force it sounded like an explosion.
