The opening time of the backend (admin view) is very long.
I counted 15 seconds.

I analyzed the MySQL process during this phase and I found a lot of queries like this:

SELECT SUM(a.hits) AS page_count FROM `#_sellacious_utm_links` AS `a` WHERE a.created >= '2020-08-20 00:00:00' AND a.created <= '2020-08-20 23:59:59'

I created this index:

ALTER TABLE `#_sellacious_utm_links` ADD INDEX(`created`);

but the opening time is not changed

No problem for sellers view because I can hide the Daily Page Views panel