Odd one this. I had smelliness when the car was new last Dec, like an electrical burning sort of smell. I put it down to dust or paint or something on the heater. It comes really soon after startup, and disappears really quickly after under 5 minutes. Once it's happened in a day it doesn't seem to happen again. It stopped happening but I can't remember when.
So this week it has just started again. I've had the heater on before this week so I don't know what has triggered it - maybe the cooler outside temp. I wonder if it's something to do with battery heating rather than cabin. It doesn't bother me, it's just unusual.
It's going in for its first service in a week so I'll mention it. The problem will be that they won't be able to reproduce it.
EDIT: This is in a LR MG5. I searched, I thought only in that forum as I'd seen it mentioned before, but obviously failed!!
It was the same in our previous ZS EV and it's the same in the new facelift model we now have.
You can ask the dealer to check it, but for what it's worth, I don't think you have a problem to be honest.
If you have not used the cabin heater, even for a few days, then when it first comes on ( for about 10 - 20 seconds ) the slight burning / singeing odour omitted, is the same as when you turn on a house hold electric fire, when it has not been used for a while.
This should come as no shock really, because they are one in the same thing generally.
That slight burning / singeing odour, when the HVAC is first turned on, did become less evident as time passed by on our Gen 1 ZS EV.
We did collect the car on the 6th of January 2020 and therefore the heater was getting used almost every single day, due to the colder winter months
Our facelift was collected in March 2022 and therefore heater use has been a lot less, until recently.
Strangely enough, I popped out to the supermarket this morning and it was very damp outside.
I was in a bit of a hurry and just booted up the car and started driving straight away.
I had left the heater turned on from the last time I used the car, about two days ago.
As I travelled down the road, I got that odour you are talking about.
THAT is when I realised I had left the heater turned on !.
After about another 10 - 15 seconds, the smell disappeared.
On the odd occasion, my wife has said :- "Can you smell something burning, oh ..... it's gone now".
That pretty much how it is, you smell it, then it's gone just as quickly !.
As you have noticed, it does not happen IF you have had the heater on a few times in the same day.
I think your are witnessing the very same situation, I hope this helps you ??.