Hello Didier,
thanks for answering me. In my question, I showed all the variantions I tried.
Your proposition was part of it. I changed the files according your Message and booted again.
No success.
You wrote “(if installed using Hacs):”
I opened the HACS Menu, which includes in Frontend the mini-graph-card, but nor in Integration or Frontend Lovelace.
I expect, that I installed Lovelace the way you described in an answer in:
Most of the time I work on HA when my wife is sleeping, so my brain is maybe near this state too.
What now?
Thanks, Peter