Last night I spent hours trying to shop on Coto Digital, the online store of Coto.
Frustrated by the many attempts, I found out that also Dia has an online store, but it is linked to a 'Nuñez branch' (I am in Palermo) where some items are not available.
Having a Día two blocks from here and another 3 blocks from our place, it seems we have better chances to get our grocery shopping done in person, because of a bigger selection, lower price, no delivery charges and faster turnaround.
We tried also Carrefour, that implemented a 'virtual queue'. Mine was just 5 minutes long and I have to say that once the 5 minutes lapsed, the website was working swiftly.
Coto keeps crashing, and requires to login every now and then as a result. Luckily, it memorizes my shopping cart so I don't have to start from scratch every time. Between 2AM and 5AM it works, though.
On FB many people do their shopping through Rappi and Glovo. I have never tried those and I think they display the same items as on the various supermarket website, but you'd use a glovo/rappi guy to actually shop for your. I think the selection is even smaller.
Today, also PedidosYa app was not working, however the website was okay.