beppi
Check settings related to exploit protections for that app. A number of banking apps do rely on some of those settings being relaxed, and you may not have relaxed them in your private space.
One other thing to try - also install the App in the Owner profile (and, optionally, disable it in that profile). I had one App which would only work (not crash) in either Workspace or Private Space if I did that. (Never worked why, but the need to do that persisted across a couple of versions of the App (and of GOS) - and was eventually resolved in another update).