I have an app, that stores refreshToken and accessToken and I only refresh when a token is expired while user is performing an action and then i store new token back.
In the recent test, I authorized my app 2 days ago, used it once and then didn’t touch it again. (means no activity in zoom)
Then after 2-3 days when I tried to use my app and create a request to refresh token I received error that my token is expired. Which is beyond me. Because Its not the case where a new token is generated. Only I authorize my app and I haven’t touched it. as you stated that refreshToken have 15 years of expiry I highly doubt that. In case you want to investigate further, I can provide my zoom account that was authorized for the app I developed. And check the logs against it that either the request to refresh token was generated or the refreshToken was invalid itself.