Something might be wrong with your relay list. Are you using the same set of relays in both apps ?
Discussion
You have to add relays separately in each of your clients? I thought they carried over client to client
They should follow but not necessarily. I remember there was an issue where if you logged in to Plebstr with your nsec you used in Damus, it would mess up your follow lists. I know that some clients have default relays too
There aren’t any issue between Damus and Nostur for this. I try to limit where I put my nsec