The HTTP response codes are standardised, 508 is 'loop detected'. Indicating a service error or resource limit. I'd guess it'd be a transient error unless something is broken.
https://www.iana.org/assignments/http-status-codes/http-status-codes.xhtml
I don't think I've ever seen a 508 response from Meraki in years of heavy API use. Have you anything in your code that could issue high volumes of calls in a short period without following the rate limiting process?
Otherwise, if you are getting these responses only on one org, maybe open a support case to check if there's an internal problem specific to the org.
