My curse client is not updating deadly boss mods. It says it is but I get in the game and it has NOT been updated.

Switch the client to Beta install type. For the v3 client, go to manage games at the left, then use the pulldown menu. For v4 client use the Tools menu, options, games and addons tab, and switch there.

I do NOT recommend install alphas of anything, ever, unless told to do so by the addon author.

The latest version on Curse is not a beta... none of the ones on Curse ever are... it's a small bug-fix for 4.29 labelled as 4.29b but still labelled as release