DIAGNOSIS Food residue or grease has sealed the bowl to the heating base. This is common after cooking fatty foods like bacon.
FIX Let the unit cool completely. Fill the bowl with hot, soapy water and let it soak for 15 minutes. Grip the handle and the base firmly, then twist counter-clockwise while applying steady, even pressure. Do not use tools.
IF THAT DIDN'T WORK The silicone gasket around the top rim of the base may be misaligned or have debris. Inspect it, clean it, and ensure it's seated properly before trying to re-attach the bowl.
HEADS UP Forcing it can crack the polycarbonate bowl. Always ensure the bowl is clean and dry on the sealing surfaces before reassembly to prevent this.