Hi! I built a query (mysql - mariadb based) usefull to fix all data set from first row.
My first row was at 11.00 so start from a posive value, you have to customize this dataset to adapt to your situation:
@original_total := 11.25, // starting value, first row, you can set what you want here
@first_state := 11.25, // use same value of previous row or a higher value
@prev_state := 0,
@first_id := 1492, // id of your first row, with sum and state equal to 11.25 in this example
@meta_id := 116, // metadata id
you can adapt it for statistics and short_term, just change table name and fix variables! 
Hope it will be usefull!
UPDATE
statistics AS s
INNER JOIN(
SELECT
myid,
cumulative_sum AS mysum
FROM
(
SELECT
t.id AS myid,
t.start,
t.state,
t.sum,
IF(
t.id = @first_id,
@running_total := @original_total,
IF(
(t.state - @prev_state) < 0,
@running_total := @running_total + t.state,
@running_total := @running_total +(t.state - @prev_state)
)
) AS cumulative_sum,
@diff :=(t.state - @prev_state) AS diff_state,
@prev_state :=(t.state) AS prev_state,
IF(
t.id = @first_id,
@risultato := @first_state,
@risultato :=(t.state - @diff)
) AS risultato
FROM
(
SELECT
*
FROM
statistics
) t
JOIN(
SELECT
@original_total := 11.25,
@first_state := 11.25,
@prev_state := 0,
@first_id := 1492,
@meta_id := 116,
@diff := 0
) r
WHERE
metadata_id = @meta_id AND id >= @first_id
ORDER BY
t.id
) d
) m
ON
s.id = m.myid
SET
s.sum = m.mysum
WHERE
metadata_id = 116;