The app can still be used too but requires the per-app secure spawning toggle with recent app versions. It's due to PayPal shipping buggy anti-tampering code.
It's not specific to contactless payments. It's a bug in the app and still works with the per-app spawning toggle disabled. The per-app exploit protection compatibility mode sets all these toggles to the compatibility mode but it's best to figure out the minimum required.
I use latest Aurora Store PayPal version and it still works. I just dont use contactless payment.