Pre finished tv cabinet bottom plinth paint damage/bubbling

[Michaelsf90]

It's more out of curiosity but does anyone have any idea what has caused this damage/bubbling to our tv cabinet. I've attached pictures. Is it because it's cold in winter in this corner near the window/patio doors? I can't say I've noticed it before when cleaning but I don't look and just wipe it down. The front and other side are fine. Just curious as to is it the cold from the window causing condensation more likely?

 

[Why Not Indeed]

Have you pulled up the carpet to see what state it's in below?

 

[RandomGrinch]

It appears to me as if the chipboard has gotten damp; the chips have expanded and pushed their way through the surface finish.
It would be interesting to know if the bottom edge of the unit is sealed, or if the chipboard has been left exposed...

 

[Michaelsf90]

Sorry for the slow response. I clean the cupboard every week so I may have sprayed it from time to time. And @RandomGrinch is right. It isn't sealed at the bottom. Probably the culprit