You need to provide some more info in order to get better answers. For example, how much traffic are you getting or what's your CR? Anyway, with all being said, there are several things you can do to increase your traffic and CR.
First, as you've mentioned, it's about language and localization. If you advertise in a Spanish language geo and it redirects them to an English landing page, that could definitely affect the conversion rate. So, let the landing page be in Spanish or the main language that your target segment has. Make source, clear, culturally relevant language, and tone. While your landing page may be in Spanish, if the offer page is not it can seriously confuse or turn users off from converting, so this is the second thing you need to fix.
Next, ensure your traffic belongs to the right demographic for adult dating offers. Adult dating offers interact better when targeted toward a male audience aged between 18-40 years, depending on the region. Also, make sure your traffic comes from countries where adult dating offers are performing well, such as the US, UK, Canada, Australia, or specific European and Latin American countries, especially in the event that your LP is targeted to capture Spanish-speaking users.
Offers of adult dating will perform better on mobile, so make sure your source of traffic delivers visitors with a friendly approach towards mobile and your LP is optimized for mobile devices.
Your sources of traffic should be adult-friendly as well. It's clear that not all sources of traffic convert well for adult offers. Networks such as https://www.trafficjunky.com/, https://www.exoclick.com/publishers/, or https://trafficstars.com/, perform better for adult offers.
Finally, if you're receiving clicks but not conversions, traffic is not in the right form converting so, look for signs of traffic sources where users are looking for adult content or dating offers since these visitors are most likely to sign up with your offer.
Hope this helps and good luck : )
