Brake/wheel issue advice please SKODA ROOMSTER (5J)

I have owned by 2008 plate roomster for a year now. It wasn’t very loved in a past life and I have had to have numerous bits replaced. The latest issue is an intermittent squeal coming from the drivers side front which I think is brake related. The brakes, discs and wishbone including ball joint were replaced in the summer with no problems at the time. Now a squeal has developed when the car is warm so it doesn’t happen first thing. More noticeable when driving slow or turning right. When I apply the brakes the squeal stops. I took it to a garage last week who had the caliper off which the piston pushed back ok. The gent took out the sliders and greased them up. This has not cured the problem. Has anybody encountered anything like this before or could suggest what the issue could be please? Thank you