‘Graphic>InvertImage’ behaviours not saved or executed

I sometimes find that the Builder does not ‘keep’ (does not save/record) my additions of ‘Graphic>InvertImage’ behaviours. Also, on occasions when it does appear to have recorded them it doesn’t use/invoke them (despite them being in the middle of a larger behaviour chain - with a Target assigned) that otherwise executes all its other behaviours as it should.
I am using IB version 3.3.3 Build 325. Many thanks