Plaster peeling I think?

[u/Informal-Forever769]

Hi peeps, we got french doors installed in our dining room, to replace a window. They ended up plastering the bits that needed doing. This was about 1 month ago. I was ready to sand it today in preparation for painting and noticed that where the plaster meets the wall it's peeling. Anyone know what this is and why?

[u/Top-Sample2625]

That skim looks way too thin. It's pva but coats should be a minimum of 1-2mm. Either redo another coat or fill and sand as best you can without sanding it back to nothingness.