Problem with sticking after 4 prints (Ender 3)

Hi, I just bought a Ender 3 and printed four almost perfect prints. They stuck to the bed so good I almost could not remove them.
Then all of a sudden I cant for my life get the prints to stick. Same settings and everything, I even changed the filament.
I removed the PTFE tube just to check that there wasnt any issue there.

See the two attached photos.

Thanks for the help.

UPDATE: Moved the print to one of the corners to check the bed. Still the same wierd result. The upper part looks good. (picture 3)