According to the operating instructions (page 40), this is indeed the case:
https://www.kenwoodworld.com/Global...

Function/ attachment = Maximum operating time
- Mixer/Blend-Xtract = 60 sec.
- Heavy mixing in the bowl (e.g. dough) = 60 sec.
- Compact chopper/grinder attachment = 30 sec.
- Spice grinder = 60 sec.

Resting time between operating phases = Disconnect the appliance from the mains and let it cool down for 15 min.