Why does the Raft adhere too strongly to the print bed?

The adhesion between the raft and the print bed is significantly influenced by the Z-offset. If the Z-offset is too low at the start of printing, the filament is pressed too hard onto the print bed, resulting in excessive adhesion between the Raft and the print bed. In this case, you can try to scrape the raft off the bed with a spatula (beware of the risk of cutting!), soak and/or remove it with isopropanol, or reduce the adhesion between the raft and the print bed by freezing it. The Z offset should be increased before the next print start. A change of just a few 1/100 mm may be sufficient.