Importing Recurring Donations - GateWayPaymentMethodID & Stripe?

Background: I've watched the enablement, walked through the steps. By all accounts Elevate is working fine and can process donations with Stripe as the gateway. I just can't get donations imported.  I am working with a client and we are at the final phase of the project, all thats left to do is to import recurring donations to Elevate. They are currently using Donor Box as their online giving platform and want Donor Box monthly giving migrated to Elevate. To reiterate: They are staying with Stripe so all that's changing is the giving platform. 

Getting the required fields like Customer ID through Stripe was easy enough, and I managed to get a next month timestamp from Donorbox, but when it comes to the GateWayPaymentMethodID we are getting the runaround.  

Stripe says Donorbox has that, Donorbox says Stripe has it, and I can see Stripe has a Payment Method ID on each payment through their front end but its not exportable. They also have this value in their API. So I am not really sure what is going on here.

Regardless, I manage to scrape together all the required data (or so I thought) through both vendors and by grabbing the PaymentMethodID through the front end on Stripe (by going to the prior months donation and using its Payment Method ID. It's a string starting with "pm_").

 Unfortunately, I am getting an error in the file that Stripe says the Payment Method ID does not exist - so clearly a dead end. I have also tried the specific card ID just to try it but same - no dice.  The customer ID seems to be working fine.

Has anyone here imported Recurring Donations with Stripe staying as the same gateway, and  able to discern what part in the process am I missing to move these payments over? Is the GateWayPaymentMethodID Stripe's Payment Method ID or is it referring to something else? Do they need to be retokenized or something even if its staying with Stripe as the endpoint the entire way? Stripe seems to have no idea what it is when my client asks their support.