PIP. DWP refusing to make decision so cannot appeal

I have a client who is accepted by DWP as medically eligible for PIP. However his award from 2019 was stopped as they said he had left GB without good reason and for too long. We just did appeal and he won though DWP seeking reasons. They didnt bother to attend at appeal!
That old award was till 2022 only so he put in a new claim then. The old appeal papers refer to the 2022 claim but just say that they cannot decide it as need more evidence from client to show he is in GB. They say he would be medically eligible.
So there is no decision still on his 2022 claim. So I cant see how we can appeal. Can they just sit on it for ever? I have written to them and I am putting in a complaint but complaints dont get much response.
As a lawyer I thought of JR but I am a volunteer and we dont have the resources to do this and I dont know of anyone around Rotherham who could do this
Am I missing something or has anyone any ideas?

Is there a template pre-action protocol letter here that could help:

https://cpag.org.uk/welfare-rights/judicial-review

Are we looking at 2 separate (alleged) periods where the claimant didn’t meet the presence conditions?

Has there been 2 appeal hearings?

EDIT: As I understand it:

So there was a 2019 claim. It was refused on presence grounds. You successfully appealed this, but DWP have requested reasons. That needs to run its course. 

In any event, the 2019 claim was a fixed period award to 2022.

There was a second claim in 2022. DWP have delayed making a decision because they are seeking evidence that the presence conditions were met. You have provided this evidence, and chased a decision, including by submitting a complaint.
I agree with Sean the solution is JR (or possibly informal resolution via MP or partnership manager etc).

If he meets the conditions now, I’d also consider submitting a new claim.

Ta for this. A JR letter before action might be an idea but I am reticent to do a if not going to take action.
On next post. There has only been one appeal hearing on 2019 claim which they then issued supercession as from 2020 and that appeal was just heard and he won. Since that original award was only till 2022 he had to make a new claim. It is that new claim where they have just made no decision. However they refer to the new claim in the appeal papers from the 2020 appeal and say medically eligible but cant decide it as client not shown in GB
Does that make sense?

I’m a bit lost in all this. When and for what duration was your client out of the UK and what further information is now being asked for? Is it to do with past presence rather than simply being a question of whether he is physically in the UK which can be verified by popping into the jobcentre with some ID surely?

Thanks Elliot
The tribunal found he was out of UK between Feb and July 2020 and he was having medical treatment
In those appeal papers the DWP say that they cant sort out if he is living in UK or Slovakia. They are just sitting on it. I dont know why they cant get him into Jobcentre and I have supplied medical records showing in person medical appointments from 2020 and ongoing.
They say they need to sort out if living in UK but they are doing nothing to find out and wont make a decision. It would be fine if they issued a refusal saying he hasnt proved he is living in GB and I could then appeal
Duncan