[PLUGIN] MPD OLED - installation & configuration plugin

I have someProbs with the Plugin and wonder if you could help me out.
I´m not very into Linux and this all stuff btw.
(See also Newbie Problem: Failed to open Alsa)

System as following:
RPI 3B+
IQAudio Pi DigiAmp+
mpd_display plugin with a ssh1106 SPI oled-display
Volumio and PlugIn latest version

My problem is as following, at first power up, Volumio displays an error “Failed to open “alsa” (alsa); Failed to open ALSA device “volumio”: Device or resource busy”

To get my system working, I enter System-Playback, turn off I2C and change the output device to “Headphone”, store this setting, play anything for about some seconds and switch I2C on again, select “IQAudio Pi DigiAmp+” and restart the system.
After the reboot, the system is working proberly without errors. Until I switch off. Then the procedure starts over again.
I also have tested it with a Hifiberry DAC+, same behavior.
Changing GPIO´s brings no other result.
Version 1.08 brings no changes.

Without any hat, absolutly no problems. I even setup a completely new systemimage.

Any help?

Greetings
Peter