They say there are bugs in the invitation process in this OJS version. There’s also some kind of problem with ORCID and invitations. Maybe you’re encountering one of those issues.
The editor dashboard in 3.5 looks so cool, but the bugs spoil all the fun. IMHO 3.5.0-1 is sooo not ready yet to be an LTS version… guess for now we’ll have to wait for the developers to fix things.