Getting 401 after successful token refresh in .NET

Is there a hidden clock skew issue in the CXone .NET SDK? I’m getting a 401 Unauthorized immediately after the library auto-refreshes the access token. My server time is synced via NTP, but the API rejects the new token. The refresh returns 200 OK with a valid JWT, yet the subsequent GET /api/v2/users/me fails. I’ve checked the ‘exp’ claim and it looks fine. Any ideas?