DIY Doctor UK DIY Forums

Hi. We had an internal wall taken back to brick and replastered a year ago. It was misted and painted white while we finished other jobs. It's now had several coats of blue-grey paint but we've been left with weird streaky white ghost or tide-like marks along the bottom of the wall. Does anybody have any ideas what may be causing this, please? The wall does not appear to be damp. The bricks were powder dry. No other wall in the room is affected. The marks cover better when the paint is brushed on but when you put a coat on with a roller they come back. We've tried sanding back and redoing, a new tin of paint and a new roller. We wondered if it may be sanding dust from the skirting boards but we have not had issues anywhere else and hoped sanding back the wall paint and cleaning it would resolve that if it was the issue. Thanks.