What is wrong with my LG washer dryer "delay end" function?

Hopefully someone can tell me I'm not going crazy because this issue is starting to do my box in!

I have an LG FWY937WCTA1 (13kg / 7kg BIG In™ Washer Dryer, White) and initially we were quite happy with it.

https://www.lg.com/uk/laundry/washer-dryers/fwy937wcta1/

However having used it for a few months it has a few weird issues that our old machine did not have, mostly related to the timing of the "delay end" function.

We have cheap energy between 01:00 and 06:00 so I want to have any dryer stuff (sheets or towels mostly, we have a dehumidifier we use to dry normal clothes laundry) going between then but the delay end is so unreliable.

I know the timing of cycles is not an exact science and depends on dampness and weight of the load but here are a few examples after I found the machine running on for hours after it should have:

On a low temperature dry I set the delay end for 7 hours at 22:15 so it ends at 05:15, when I got up at 06:15 I looked at my Home Assistant energy usage and the machine did not start until 04:04 - there is NO WAY this programme is finishing in 1 hr 10 min! I've found this programme usually takes around 2.5 hours.

Last night I set the machine to delay end for 04:20 thinking this would be enough buffer for its weird grasp of time - I wanted a cupboard plus dry this time, something that takes around 4-5 hours with a half load of towels, again I'm just up and it's not due to finish until 08:00 and running 2 hours into the peak energy tariff pricing. Home Assistant tells me the dryer did not start until 03:10, thus it gave itself just over an hour to complete the load.

What takes the biscuit though is last week I set a 2 hour dry - there should be no messing here, that should take 2 hours and that's it. We also have a cheaper energy price between 09:30 and 11:30, so I duly set the machine at exactly 08:30 to end this 2 hour dry 3 hours later at 11:30. What happened though is the machine started at 09:10 and duly finished 2 hours later at 11:10! So it couldn't even work out how to end a 2 hour programme 3 hours later?!

Something clearly wrong here, just wondering how I should be approaching this with LG (it's only a few months old) and whether this is maybe just par for the course with this model or whether the machine needs some kind of reset to kick its internal chronometer up the backside?