What's going on?

kde-open5 is breaking the links by making all characters lowercase.

Get the link by running:

while sleep .1; do ps aux | grep slack | grep -v grep | grep magic; done

Then just run `xdg-open [the link]`

The link should look like this:

slack://T8PPLKX2R/magic-login/3564479012256-b761e747066f87b708f43d5c0290bb076f276b121486a5fb6376af0dd7169e7d