HI,
We are also facing the same issue.
We just started using Paypal payments and these are two things happening right now:
1. We disabled the old plugin but were still not able to complete the payment for the First time with New user without login.
2. When a user is logged in then payment is getting successful without any error
When I see logs I see lots of errors in every row:
ERROR Illegit Webhook request detected
Tried everything like install the plugin again, Connected Paypal again but nothing worked.
Please help.