Kodi Seren add on

I have Kodi 18 Leia (latest) in one room, and Kodi 17.6 Krypton in another. Seren (latest 2.0) working seamlessly on Leia, but “couldn’t connect to repository” on 17.6 Krypton set up. I’ve removed nixgates source and repo, re-nstalled, but same issue. Might do a fresh Kodi install of 17.6, and see if that fixes?