Ok, I think I understand the issue now. This thread from 2.5 years ago seems to be about the same thing.
While far from ideal, until the issue is officially addressed by Bubble, another approach might be to implement a “proxy relay” endpoint - i.e. a “middleman” endpoint which sits between Bubble and the “true” endpoint (Stripe in this case). For certain “critical” API workflows, it might be worth the effort.
I fiddled around and was able to implement a no-code solution to fetch a customer from Stripe with error handling using Integromat for the proxy endpoint…
It all works as intended. When the Bubble endpoint is hit, a new entry appears in the DB if a Stripe customer is found; and I get an email if Stripe returns a “No customer found” error.
Anyway, I can share more detail if interested, but I thought I’d pass it along.