There is a difference between the ends made for solid conductor and stranded conductor. And there are also ends that claim to work on both.

The stranded conductor ends have straight teeth, that pierce into the middle of the cable.
The solid ends have staggered teeth meant to wedge the solid core (much like an IDC connection).
The ones that claim to work on both are usually a 3 tooth version of the solid. And I personally think its sketchy they market it like that.

As long as you got the correct ends on the cable, shouldn't be a problem. Get the wrong ends on and you might get it to work now, but it might not work in the future.

As far as the cable goes.... Since stranded is usually for patch cables, I don't think I have ever seen a stranded cable rated for outdoor use (direct burial or otherwise). So I think it likely that cable will end up needed to be replace in the coming years. Unless it is something I haven't seen before and is rated to withstand the elements it will face.