I found your site via another post of yours and had a look. A few thoughts (bear in mind I'm not your target customer and don't look at sites in this niche often)
- I think conversion rates have been dropping for B2B SaaS largely across the board over the last 1-2 years, so you're definitely not alone.
- I'd tighten up the hero text (esp subtext) — take your biggest benefit from user feedback and focus on that. You describe the chat as available for certain times but I have no idea what time zone you're in.
- Revamp the customer (google) review section — the texts are clipped and don't clearly show what they've gained from using you.
- Your /en site has an app preview in a different language. If you're targeting ads in En markets, this may be a last-minute turn-off.
Hope this helps, and I think you're onto something with the 'broad approach' problem. Mb spin up some test landings that are much more concise and target a certain niche, preferrably one where you already have some happy users.