The hack provided in the ticket https://forge.typo3.org/issues/62194 does work fine until TYPO3 7.6 but only works partially under TYPO3 8.7. It sometimes works in Firefox, but does not work in Edge or Internet Explorer.
The code currently used is:
$GLOBALS['TSFE']->fe_user->checkPid = 0;
$userRecord = $GLOBALS['TSFE']->fe_user->getRawUserByUid($userId);
$GLOBALS['TSFE']->fe_user->createUserSession($userRecord);
$GLOBALS['TSFE']->fe_user->setAndSaveSessionData('tx-datamintsfeuser-autologin', TRUE);
Do you have a solution which works in TYPO3 8.7 without the need to write a login service?
I am asking this question here because I am looking for a solution for https://forge.typo3.org/issues/83565