start date of CTR

Cl was in receipt of UC and in employment but lost her job due to domestic violence. She finished work on 2/4/22 but her final salary payment was made on 28/4/22. She made a claim for CTR which was initially refused due to various things but later awarded after she requested a review. She asked for it to be awarded from 29/4/22, the day after her final salary payment (which took her above the income threshold for an award). However, it has been awarded from 13/5/22 which is the start date of the first UC AP after she received her final salary payment. Is the council (Calderdale) correct to use this start date?
Ch.3, 38 and Part 13, 108 seem to be the relevant sections but I can’t make out how this is covered here?
https://www.calderdale.gov.uk/v2/sites/default/files/Council-Tax-Reduction-Scheme.pdf

if she was getting UC while she wqas working, then most councils will use the UC figures -  so would use UC and earnings for that UC period -  they would then check the following UC period to see if she quaklifuied. She did.

They wouldnt end the earnings from 28th Apriul because they aere using the monthly UC award to base the CTS on rather than a week on week income .

its in there scheme - para 38

Calculation of income and capital: persons who are not pensioners who have
an award of universal credit
38.—(1) In determining the income of an applicant—
(a) who has, or
(b) who (jointly with his partner) has,
an award of universal credit the authority must, subject to the following provisions of
this paragraph, use the calculation or estimate of the amount of the income of the
applicant, or the applicant and his partner jointly (as the case may be), made by the
Secretary of State for the purpose of determining the award of universal credi