"Pedrx",
If you found a product or solution for the this problem, please update. I've run into the same thing on a little paint project. Frustrating!
Two members of another forum recommend this Zinsser Peel Stop too. I got a price locally of about £7 + vat per ltr. Not tried it yet.
Perhaps where I was going wrong was trying to cover the peeling area with fine surface filler – Easy Sand Joint filler – to conceal the different levels before painting.
I was using the slow drying joint filler which with the present weather took 2 days to dry and hence, presumably, more opportunity for water to creep under the paint and loosen it.
Before buying Zinsser I tried sealing 3 test areas of the peeling area with, separately, Pva, Acrylic Varnish and thinly applied emulsion all of which dry fairly quickly.
There was a little further peeling which needed scraping and painting again before applying the Easy Sand and the damaged area is now repaired successfully.
Probably the Pva worked best but is not easy to sand.
This was a mild case of peeliness. If you’re suffering from terminal peelyitus and particularly if the wall is damp then you might try the Zinsser which is supposed to be micro - porous to allow the damp to escape. Mind you so is acrylic paint and varnish supposed to be micro - porous.
On a different aspect of the subject I find the draw scraper with a tungsten carbide blade is more efficient than a ‘push’ scraper. Like the old Scarsen scraper which worked well but the blade soon went blunt.
The TCT blades can be sharpened, on the handle, with the correct green grit wheel on an electric grinder or diamond blade on an angle grinder. I reuse the old blades from my standard wood planer which can be snapped to length.
The above has probably not solved your problem but at least it has given me chance to waffle.
