Hello there,

We are the developers of the One-Click Upsells plugin by WooFunnels and from the past few days we are getting the report of our integration with WC Payments broke and upsells are no longer running.

When we checked further we are able to identify the issue, the issue is token saving code is moved down after payment_complete runs and this caused failure in our checks for token validation before running upsells.
This is the PR that contained the change that caused the issue #3118

So we suggest if it could be rolled back to the earlier version of code OR will be handled in such a way that for the non-webhook environment we save the token to the user before WC_order::payment_complete() runs.