Damp seal and paint finish

[Hedges85]

Hi all,
Recently finished decorating my living room, i have a slight issue with the finish though. As you can see in the pictures I have a patch where I have previously applied polycell damp seal due to a previous issue.
I thought painting over this would be fine however it appears it isn’t, I used Valspar v700 paint.
Is this a paint issue? It’s had 2 coats. Any suggestions on how to get a better finish would be greatly appreciated.

thanks
Scott

 

[bobasd]

what was the previous issue?
is that wall cavity or solid, and is it externally rendered?
how close to the window reveal is the patch?

 

[Hedges85]

There was a previous damp issue, this was caused by the french door that sit directly below and to the side of it. These have now been replaced as of last week.
The patch is caused by the polycell damp seal paint I previously applied, I need to user stand how to cover this.