Duplicate member created with same email: 1 paying, 1 free

Running Ghost 4.3.3 with sqlite3, Node 12

I see in my members that there are two profiles with the same email: one is paying (and therefore has Stripe Id and first/last name), while the other is free. (so no Stripe ID, no first/last name)

This seems to be a bug, such a duplicate user should not be created.

This user also has trouble loggin in, with this error message:

image

What causes this particular error message?

Please help!

bumping coz it might be a bug!