There is no analytical solution.
Warning: Unable to solve symbolically. Returning a numeric solution using vpasolve.
> In sym/solve (line 304)
So solve tells you that it used a numerical solver. That you want it to find all solutions is not that mathematically relavant, unless you are good with a magic wand.
You can use a numerical solver, starting from different start points, then collect all solutions found. But wanting the impossible only makes you a dreamer.