Hi there Paul - same issue here for me too. Alas this is part of the security features our hosts have introduced. Though a little bit inconvenient, It should be a relatively automatic feature?
On the plus side, selfishly, it is saving the mods from dealing with the 100s of fake / bot membership applications we used to get on the site every day (I'm not kidding, it was that bad).
Hopefully it is but a small nuisance only
Cheers,
Brad C