I thought my SaaS wasn’t converting — it turned out to be a mobile UX issue

I’m building a small B2B SaaS in the local SEO space.

Over the last few weeks, I noticed something that didn’t make sense:

People were signing up

But a large percentage never completed even one core action

At first, I assumed it was:

Poor onboarding

Wrong audience

Or weak value proposition

But when I dug into behavior more closely, I realized something embarrassing.

Most of my users were coming from mobile (Facebook, DMs, groups), and on smaller screens the primary action button was either:

Hard to notice

Or visually pushed below the fold

So users signed up… then quietly dropped off.

Once I fixed the mobile UI and made the primary action obvious:

Users immediately started completing actions

Trial usage increased

And the “silent” drop-off finally made sense

Lesson learned:

For early-stage SaaS, conversion problems aren’t always pricing or features — sometimes it’s just a tiny UX detail, especially on mobile.

Curious:

How early do you test mobile UX for B2B tools?

Any simple ways you validate “first action completion” fast?