Make TK (Techniker Krankenkasse) app working again

Basic info

• Device: FP4
• CalyxOS version: Android 14, CalyxOS 5.14.2

Brief description of the issue

The TK app does show this at startup:

P2 - Request failed: An unexpected issue has occured with your Google Play Services.

Steps to reproduce

Install de.tk.tkapp from Google Play. https://play.google.com/store/apps/details?id=de.tk.tkapp&hl=de https://www.tk.de/techniker/leistungen-und-mitgliedschaft/online-services-versicherte/tk-app-2027886 And start it.

AFAIK no account is needed.

Expected result

App should start.

Actual result

Any other info

Upstream microG issue is https://github.com/microg/GmsCore/issues/2617

I only opened this because in https://github.com/microg/GmsCore/issues/2617#issuecomment-2691205893 someone claimed to have found a solution respectively the changelog of e/OS/ confirms they apparently included a fix in https://gitlab.e.foundation/e/os/releases/-/releases/v2.8-a14

So maybe you can do, too? It's unclear what the specific fix there is, until yet, though.