There's nothing bad about that, especially if you haven't spent half your life focusing on those leetcode type problems. Consider that a typical undergraduate "data structures and algorithms" course runs for a whole semester and doesn't actually (usually) cover that many individual algorithms. You might study one DS / algorithm in one lecture session and then have a few days to spend working on homework involving it.

I forget solutions within hours of learning them.

Fine. You don't really memorize the specific solutions to these things. You internalize the concepts to where you can recreate the solution when you need it. You don't have to remember all of the details, just enough. And that takes practice.

After 1 month of trying to solve problems on leetcode.com, while taking a coursera course ... I am NO BETTER at solving these problems.

A month really isn't that long to spend on this stuff. Give it six months, and if you don't see any improvement, then maybe that tells you something meaningful. But right now, this seems like the equivalent of going to the gym for a couple of weeks and then complaining that you aren't a world class power-lifter yet. It takes time to achieve results.

I need to see improvement, but it's just not happening.

Two things:

1. I'd encourage you to give yourself more time (but keep working hard)

2. Your entire premise might be wrong. Not all jobs require doing leetcode/hackerrank style problems. Now if you're in the SV area, and you're focused on working for trendy startups it might seem that way. But jobs in other areas (the East Coast of the US is where I'm most familiar) don't always, especially if you're willing to work for a company doing something a bit mundane, like retailing auto parts, or life insurance, or something.