How to scale pop traffic campain (ZEROPARK)

hi to everyone, i have a successful pop traffic campaign, i spending 40$ and making 60$, is already optimize, but now i what to understand how i can scale the campaign.
i was thinking about upping the budget about 20% every other day.

i asking this question because 2 week ago i had a campaign with 200$ daily budget that make 80% ROI, but after i double the budget (400$) the campaign pass from 80% to negative ROI overnight.

thank you