Member confirmation / reset password emails not working

Hi,
I’ve just launched a new website, and thought I had the WP Members plugin up and running fine – I signed up a few times to test it and received subscriber email/password confirmation and notification to admin of new users.

After updating various plugins, I am now not receiving any emails – either to subscribers or to the admin to show user registration.

I’ve tried deactivating all other plugins. I’ve tried signing up from 3 different devices on different wifi connections.

I’ve re-installed a fresh download of the WP Members plugin.

I’ve made a temporary fix of letting new subscribers select their own password on sign-up, so they don’t rely on receiving a password by email, but this isn’t ideal, as password reset emails aren’t getting through if they forget their password and they have no email trace of signing up.

I’ve cleared cache during testing and have had failure for 4 days (ie not just re-testing repeatedly on one device over a short time)

I’m not sure what else to try!
Hosing with one.com and they don’t suggest any issue of their side.
Any ideas about what could be wrong would be much appreciated.
Thanks

The page I need help with: [log in to see the link]