Membership: post-gateway issues

Just starting a new thread

Membership works fine for me, up to payment processing - where members are able to pay but are not added to the right subscription (ref. this issue.)

During my test registrations, I can see the amount being actually taken from my PayPal account, and the transaction does appears in my gateway with the correct subscription - but as 'pending', and not just once, but 3 times (but same transaction ID). I also show up in the members, but assigned to the default free 'Just visiting' subscription rather than the paying '10K' one I had selected (see attached).

I'm using Paypal Single (other gateways inactive), I've got the latest WP/BP/membership installed (on multisite), wordpress registration disabled, and I've run the 'repair tables' add-on. I've also manually checked my tables and they've got the 3 transactions but nothing in the 'payments' table.

Any idea what else I could try? Cheers