Hi David,
Yes, indeed, a common problem with 3200s.
In 16 years of ownership I am on my 3rd sender.
Mine reads 5 bar until warm, then drops to a consistent 3.5-4 bar and every once in a while will go into a frenzy for a minute or so as the gauge flicks from 0 to 4 and all over the place and then settles down again.
When I got a new sender, it would be absolutely fine for a few years (between 3-5).
Obviously, this is something which is important to work properly, but with availability issues etc. we just have to live with.
I believe there may be ‘other solutions’ available.