The thing is, no ultracompact stroller sits totally upright. I am sorry, but that is their "price to pay" for the absolutely minimal fold and small size.
The Joie Pact is, actually very very slanted so the exact opposite of what you want. It is also because it is quite cheap, and so their saved their expenses where they could.
If you want to look at some other ultracompacts, check our top 2021 ultra-compact stroller suggestions in this article, I'll pinpoint models like Mamas&Papas Airo, Chicco Goody (full Chicco Goody stroller review here, Ergobaby Metro Plus - they are more upright then most, but never expect a completely upright carry-on stroller.