[Need Help] Foam Board / PS Board / KT Board bubbling problem with SAV

[Acotop]

Hi guys,

I have a problem with chinese KT board/ps board. I applied SAV/vinyl sticker to the foamboard with mounting machine and after few days it started to bubbles (like the photos). Any idea why this is happening, any workaround or things that I can do to fix this? Thanks a million guys...

 

[victor bogdanov]

formaldehyde seeping out?