I hadn’t considered that it was because it was a PHEV.
I have mine set at 21.5c any higher than 22c, I find starves it of heat quickly and it goes hunting for heat by turning the engine on, but by time it’s done so I find the cabin has cooled down and always rely on heated seats & wheel as a backup. If you go searching, even on here you will find EV’s can’t meet the heat high demand temerature settings, so they have to lower the temperature and similar to wet underfloor heating, its a low and slow aproach.
The cynic in me, thinks all this evolution of technology comfort has gone by the wayside and we all have to dress like we skiing in the Alps. We have all had ICE and know for well they can’t be beaten on providing heat however, some now see that form of heat, as wasteful and bad for the climate, but us humans won’t stop the interglacial period and what comes next, but it’s a very good money racket and if at all leaders were serious, they would have been outraged at the cutting down of part of the rainforest, to build a road to COP30 and would have conducted meetings on teams and not took a jolly on a private jet. I could go on..
As for your aircon, it probably needs topping up like mine did.