Spurious supports - why are they generated? - how to get rid of them?

[Flying_Roger 0]

In several models, I got spurious supports generated by CURA 4.8.0
By "spurious", I mean that these supports does not seem to support anything.

 

I tried to get rid of them using the "support blocker" tool, but to no avail.
As the support blocker acts on the model, not on the cura engine, you cannot select a support for deletion: instead, you need to mark the area that triggered the support.
However, how can I do that for supports that do not support anything? It is hard to figure out which area of the model triggered them...

 

Here attached an example, generated with the parameter "support angle = 55°".

On the last picture, you see that a support is "hanging in the void" almost without any contact with the structure.

I appreciate CURA, but I have only a few months 3D printing experience, so sorry in advance in case I missed some basic knowledge.

   

Edited January 31 by Flying_Roger

[fvrmr 11]

Do you need everywhere support? Because you can change support placement to touching buildplate. With the option everywhere it will also print support on the model. 

[GregValiant 203]

They aren't there to support that radius feature because it is more than 55°.  My guess (since they are rectangular) is that they are attempting to support the rectangle above.  Moving the support blocker up higher might help.

[Flying_Roger 0]

Thank you for your replies, but:

- I need to support everywhere because there his a horizontal cylinder hole higher in the object and it needs internal support.

- How can the "unwanted" support support something that it does not touch??? 
- I tried to use the support blocker, but it is very hard to use because it works indirectly instead of simply clicking on the support that you would like to delete.
The only way I found was to set the angle to 75°, but I wonder whether the cylinder hole will be printed correctly, and it is only at the end of a long print that I will figure out...
 

[DivingDuck 60]

@Flying_Roger, a little bit to late, but maybe helpful. There is a setting that forces this problem sometimes for some of my models: Support ->Use Towers

If this is activated try with uncheck it for this model.