Sum days based on status

ericsara , a new column

datediff([Date], minx(filter(table, [Date] > earlier([Date]) ),[Date]),day)

ericsara 

In your instance for development "24/5/00 to 29/5/22 (5 Days) + the difference between 31/05/22 to 7/6/22 (7 Days)." in which total  is 12 days not 11.

amitchandak 

In your solution you missed the duplicate date scenario , Admin and support both got on same date 08/05/2022.

The improved calculated column is shown below:

First add index column start from 1 in power query

Then 

Column =
DATEDIFF (
      'Table'[Date],
       MINX (
         FILTER (
         'Table',
         'Table'[Date] >= EARLIER ( 'Table'[Date] )
          && 'Table'[Index] > EARLIER ( 'Table'[Index] )
           ),
          'Table'[Date]
           ),
       DAY
)

ericsara try this

Column =
       DATEDIFF (
       'Table'[Date],
            MINX (
            FILTER (
               'Table',
               'Table'[Date] >= EARLIER ( 'Table'[Date] )
                   && 'Table'[Index] > EARLIER ( 'Table'[Index] )
                   && 'Table'[Ticket no] = EARLIER ( 'Table'[Ticket no] )
),
            'Table'[Date]
),
            DAY
)