I think that depends on the definition of "solved".

In Finland, the Onkalo repository is being steadily built out (honestly, there might already be waste stored there, I haven't checked in on that story in a while. I know there was some delay due to COVID).

In the United States, there's been a lot of the usual politicking about where to build something that doesn't exactly sound appealing to have in one's backyard. Nobody wants to be the senator who allowed the government to build a nuclear waste site in their state, no matter how safe the site actually is.

This has led to the unfortunate situation where by law, the EPA is only allowed to consider a site in Nevada (because the other sites were in states represented by the Speaker of the House and President pro Tempore of the Senate), but because Nevada became an important state for Obama to become president, the site couldn't/wouldn't actually be built there and has been on hold pretty much ever since. My armchair understanding is that the Nevada site is probably one of the better places in the United States that you could store nuclear waste, but politics has ensured it will not be put there for a long, long time.