CRC request does not arrive after changing webhook URL (domain)

api

#1

I changed the URL (domain) of Webhook I registered once.
The A record of the already registered domain used a wild card like “*.xxxxx.co.jp”.
After completing domain change and submitting a post request to register webhook’s URL again, we received the following response.
{“errors”:[{“code”:214,“message”:“High latency on CRC GET request. Your webhook should respond in less than 1 second.”}]}

However, when I access the sent url directly by the browser, I respond within 1 second.
(Example)
https://xxxxx/webhooks/twitter?crc_token=abcdefg

I checked the access log for the endpoint of the get request where the crc request is made, but the logs that were left were only the logs in the get request that I directly accessed from the browser.

I imagine that the DNS cache of my previously registered domain remains on the Twitter server machine.
Is this prediction correct?
If this prediction is correct, is there a way to manually clear this cache?

Thank you.