403 forbidden when DMing a Lemmy user

When I try to DM someone on the jlai.lu lemmy instance, I get “403 Forbidden”.

This is over Tor but doubt that’s relevant since jlai.lu permits tor, and most likely my msg takes this route:

my PC → Fedia server → jlai.lu (server)

That instance also seems to be federated with Fedia (users from there post on fedia mags). So for that reason I expect DMs to work.