429 Error from /observations/histogram API when calling at 60 calls/minute

I’ve been using the APIs in the last week and noticed I’m consistently getting “429 Too Many Requests” errors when rate limiting to 60 calls/minute (which is the documented recommendation). Also well within the other limits (running less than 1000/day)

Seems similar to these issues:
https://forum.inaturalist.org/t/discrepancy-between-documented-rate-limit-observed-rate-limit/8612/1
https://forum.inaturalist.org/t/api-inaturalist-org-v1-observations-id-limited-to-30-observations-not-200/54865

I’m going through pyinaturalist, which should in theory rate limit me, but I’ve added my own rate limiting as well.

App version number, if a mobile app issue (shown under Settings or About):
Using API via pyinaturalist (0.20.1)

URLs (aka web addresses) of any relevant observations or pages:
Primary API being used is get_observation_histogram() which is a frontend for /observations/histogram

Description of problem (please provide a set of steps we can use to replicate the issue, and make as many as you need.):

Code I’m using can be found at https://github.com/ewbing/inat_species - currently rate limits are set to 30 calls/minute (which works without error). If you change (via constants) to 60 calls it has been throwing errors.

I’ve double checked the APIs are within limits via timing the program.