Correct.

On primal you have:
2793 posts (including reposts) + 7657 replies (10450)

On nostr.band you have: 
10175 posts and replies + 127 reposts (10302) so your stats are missing 148 posts, replies and reposts which I assume is approx equivalent to the last few days for you.  For me it's less than 20 different but that fits well with the time the graph starts to flatline.