Dont do SELECT post.* when you do grouping, you need to handle column values that belongs to a group properly like counting or combining them or whatever, Then do INNER JOIN individually for each meta key to have each own column.
Paste the SQL below in your phpMyAdmin and confirm you get the result you desired then you use on it on $wpdb.
SELECT
count(post.ID) as post_count /* Count Post belongs to a grouping */
,sum(tua.meta_value) as top_up_amount /* Sum top_up_amount belongs to a grouping */
,team.meta_value as team_name /* column use for grouping */
FROM wp_posts as post
/* inner join postmeta with top_up_amount key */
INNER JOIN wp_postmeta as tua ON post.ID = tua.post_id AND tua.meta_key = 'top_up_amount'
/* inner join postmeta with team key */
INNER JOIN wp_postmeta as team ON post.ID = team.post_id AND team.meta_key = 'team'
WHERE post.post_status="publish"
AND post.post_type="team_member"
GROUP BY team_name
ORDER BY top_up_amount DESC;