I think that probably is to be expected, unfortunately. The model is 2GB; per the article iOS will kill apps that use 2GB on 4GB RAM devices (and the 13 Mini is 4GB).
It works just fine on my iPhone 12 Mini, which has (basically) the same RAM, so it seems like it's something else. They're basically the same phone in general though, so I would be surprised if it was a hardware issue.