I'm on v1.3.8 there is a "Deploy" button above your list of mods. Even if you've Enabled mods in Vortex, you need to click that button for them to be copied from your Vortex staging folder to your Bannerlord installation's Modules folder. I had to close and re-open Vortex for the Deploy button to work after I'd Enabled a mod. Might have just been a one-off glitch. You might also need to highlight the mods in the list before clicking Deploy, am not sure. Once you've done all that, you should now see your mods in the list which is displayed after clicking "Mods" in the Bannerlord launcher.
I've read that even if you do all the above, you may still not get your mods installed because your Vortex staging folder needs to be on the same drive as your game installation. So if you're still having no joy, try checking that.
