Installation failed on Nexus 9 with Magisk and MicroG

I installed the [app from F-Droid](https://f-droid.org/packages/mattecarra.accapp/).

On first start of the app, superuser prompt displayed as expected and I granted rights "forever".
The app then proceeded with "ACC installation...", and shortly thereafter I got the error message **Installation failed** with instructions to open a ticket.

I have copied the [contents of the logs directory and uploaded it to my Nextcloud](https://nextcloud.asks.se/s/SQqRRC6KJHA8A2s) (note, I have extracted the contents of the tarball `acc-logs-flounder.tar.gz`).

I'm trying to repurpose an old tablet into a webcam (using Iriun) and extra screen real-estate, so it's more or less permanently connected to power via USB to computer, and I thought the battery could benefit from a set charging limit.

Nexus 9 running LineageOS `14.1-20211021-unofficial-flounder` (Android `7.1.2`) with Magisk `23.0`, MicroG NoGoolag `2.9` with NanoDroid Patcher `23.1.2.x`, TWRP `3.5.1_9-0`, and Xposed framework `89` with XPrivacyLua `1.27`.
API level 25, kernel version `3.10.103` (razorloves), SELinux stats enforcing.

Any ideas on what could be going wrong?

Begin by reviewing the uploaded acc-logs-flounder.tar.gz contents and comparing the failure with the reported Nexus 9, Android 7.1.2, Magisk 23.0, and MicroG environment. The issue names no repository file or test; the investigation is complete when the installation failure is reproduced and its cause or compatibility limitation is documented.

Written by the indexing model from the issue text.