Hi Dave,
This is the WooCommerce code which creates the ‘customer’ role:
// Customer role.
add_role(
'customer',
'Customer',
array(
'read' => true,
)
);
As you see it contains the single ‘read’ user capability. Does your copy contains the same ‘read’ capability?
A possible problem would be related to other plugin or theme code and/or options which prevents login with role different than the ‘customer’. Try to deactivate all plugins and activate WordPress default 2021 theme. Will it change this? If Yes, then you can isolate a source of the problem activating plugins back one by one with a new login test.