Predictive routing 429s at low concurrency?

Just noticed that… hitting 429 too many requests on /api/v2/predictiverouting/campaigns when i crank jmeter to just 50 threads. running from singapore (asia/singapore). thought the limit was way higher? using jmeter 5.6.2. the error starts almost immediately after the first batch. is there a specific rate limit for campaign updates or am i hitting a global api cap? config is pretty standard, just polling status. need to know if this is a bug or my setup is wrong.