Our team is going to have a look at this, for sure. The workaround currently is to manually change the value of renewals when they are recorded on the GiveWP side.
Note that the correct amount is coming in to the payment gateway, it's just getting recorded incorrectly on the GiveWP side.
Until this issue is resolved, we'd recommend turning off Subscription Renewal receipt emails from GiveWP, since they might be confusing for donors. You could temporarily use Stripe's emails.