If the cookie is not sent back to new requests, either TIdCookieManager rejected the cookie when it was received, or does not match the accepted cookie for new requests. Can you show the actual Set-Cookie response headers that send cookies and the URL (s) that you think cookies do not send correctly? Have you confirmed that after receiving a cookie, it actually ends with TIdCookieManager before sending a new request?
What version of Indy are you using? Until 2011, earlier versions of Indy 10 did disrupt the processing of cookies, which were mostly unusable. But at the beginning of 2011, IdCookieManager.pas and IdCookie.pas were completely rewritten from scratch, and since May 2011 they worked correctly, and I did not see any new messages about the abuse of cookies.
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