Sorry, I could not find a fix for you @rmikalkenas. I only found "hacky" solutions..

I still suggest merging this and then reopen #52587

IMO it could be easily fixed by adjusting logic at

With mine introduced fix isTimeout method will no longer throw a TransportExceptionInterface, therefore retry mechanism wont be called (looks like this part wasn't covered by tests and I didn't check it as well).

Removing previously mentioned $chunk->isTimeout() call from if block solves both issues - yours and mine. Edit: it needs more changes, as we cannot blindly allow to retry all timeouts (idempotent methods etc)

In addition to that, Symfony\Contracts\HttpClient\ChunkInterface::isTimeout contract should be adjusted as well, since this method will never throw TransportException.

it needs more changes, as we cannot blindly allow to retry all timeouts (idempotent methods etc)

Yeah. Im afraid so..

looks like this part wasn't covered by tests and I didn't check it as well

Correct. That is the biggest issue.
Since I am not 100% sure what changes needs to be done to fix both issues. I suggest to do a quick merge on this one so it can be released in next patch version. Then reopen and try to fix #52587

Thank you @Nyholm.

Thank you for merging