[kanga]

These have suddenly stopped for me. It may be something I did in the 'Control Panel' or elsewhere, but if so it wasn't deliberate. They still appear once I'm logged in, though.
As far as I can see I have ticked the boxes for both for new contributions (including likes/dislikes) on threads to which I've contributed.

Grateful for any help troubleshooting ..

[kanga]

in the event, the answer was too easy, and obvious . For some reason my mail provider (gmail) had suddenly decided that Forum notifications were Spam. Adding them to the safe senders' list has fixed it.

[Ian Melville]

Thank you for seeking that solution, I was just beginning to wonder if I had a notification issue as well. Saved me some leg work