Within the same branch of the same bank, I noticed there are ATMs that know how to serve you and others that don't. On average, 1 of every 4 ATMs I tried gave me cash. Just keep trying until you find one that works. As owner of an HSBC chip debit card based in the UK, I found the following to be helpful:
1) Santander at Plaza de Mayo - any of the ATMs they have, just beware of the siesta times when they are closed.
2) HSBC just half a block off Diagonal Norte - the lowered in height ATMs, designed for disabled access. For some reason, they work with my card while the others don't.
3) HSBC on Florida - about half of them are fairly functional for me.
May not be the case for yours, but it's worth trying every single machine in a branch. After a while, you'll know your sweet spots. Good luck!