When should UC stop when Claimant is abroad for 6 weeks

cl and husband are Turkish with LTR and access to benefits
Cl, husband and two child visited family in Turkey leaving on the 22/7/23 and returning 2/9/23
Cl informed UC before they left that they would be out of country for more than one month and that they planned to have root canal procedure completed whilst in Turkey.
Both cl and husband were working before going to Turkey. Husband took unpaid leave whilst away and cl worked PT whilst in Turkey.
Cl received their usually UC payment, including Housing Element on the 14/7/23. Whilst in Turkey they realised that their payment due on the 14th August was not paid
Their UC account was closed at some point and when they returned they made a new claim starting on the 4th Sept.
Suspect it would be tricky to argue that the cl went abroad solely to undergo treatment of an illness / impairment or convalescence ?
But when should the award have been terminated, when they left the country or after one month of absence or what seems to have happened here, the day after their last assessment period?
Any thoughts greatly received as always

My reading of the regulations is that the absence must not be expected to be more than one month and must not in fact be more than one month (regulation 11 of the UC Regs 2013).  In your client’s case the absence was expected to be and was actually more than on month and therefore cannot be paid for the one month absence. 
In order to benefit from the 6 month absence the absence has to be “solely” for treatment.  In your client’s case the absence was for mixed reasons rather than solely.

If (as appears likely - questions around dates of travel, time with family, date of procedure would seem to undermine ‘solely’ as above) your client cannot bring themselves within medical treatment exception, then the date is correct.

The award was superseded on grounds of a change of circumstances (absence from GB as a result of which they no longer met the basic condition).

That supersession takes effect from the first day of the assessment period in which the change occurred/was expected to occur: Sch 1 para 20 UC etc (Decisions and Appeals) Regulations 2013.

That was of course the AP in which 22 July fell and therefore the first day of their July-August AP is correct.

Many thanks for responding Shabir and Alex, very helpful as always tho of course not the answer the cl was hoping for