Your LSA spend can increase without a similar increase in customers if the campaign is generating more leads but those leads are lower quality, or if your lead-to-customer conversion rate has dropped. Changes in competition, demand, service areas, lead mix, budget, and bidding can also affect results.
Start by comparing your recent performance with an earlier period. Look at total spend, leads, qualified leads, booked jobs, close rate, and revenue. If lead volume increased but customers did not, the problem is likely lead quality or sales follow-up. If leads stayed flat while spend increased, check CPL, bidding, competition, and campaign settings.
The key is to find where the drop is happening before increasing or reducing your budget.