1. Summarizing the problem
No display (https://www.amazon.de/gp/product/B07XPM2ZS3) after LVM tutorial anymore.
2. Providing details and any research
After using this Tutorial (Easy backups and snapshots of a running system with LVM) from Ingo (https://raspberrypi.stackexchange.com/users/79866/ingo) everything was/is fine with my Raspberry (Raspberry Pi 4 Modell B; 4 GB, ARM-Cortex-A72 4 x, 1,50 GHz, 4 GB RAM, WLAN-ac, Bluetooth 5, LAN, 4 x USB, 2 x Micro-HDMI ) with a Raspian Buster, Pi-hole, Wireguard installation beside not having a Bruphny 4.0 display anymore (https://www.amazon.de/gp/product/B07XPM2ZS3). Still access to the cli. The display is just turning on and off in intervals.
3.Describing what I’ve tried
Tried to redo the whole LVM installation but came out with the same result. The display is recognized by the Raspian Buster default Installation.