Hot end crashes into bed when Octoprint connects

What is the problem?

New SD card, fresh install using the latest Pi Imager downloaded today 25 May 2022).
Set up Geeetech A20 printer (255x255x250, front left origin, heated bed).
Select AUTO for all connections and click Connect.
Printer resets (!) then connects then immediately starts lowering head to print bed (with a grinding sound from the stepper).
Ignores the BLTouch probe and continues down, crashing the hot end into the print bed and then attempting to continue lowering until I power off the printer.
The terminal log shows this command response from the printer:

Unknown command: "ª\x19\x10"

Absolutely repeatable every time.

What did you already try to solve it?

Reset connection.
Checked Z-offset (correct)
Ran BLTouch self test (passed)
Reimaged card and re-setup.
Problem remains.

Have you tried running in safe mode?

Yes, in safe mode the behaviour is different but still odd.

Did running in safe mode solve the problem?

Hit Connect
Printer resets ()
Octoprint connects
Hot end raises around 15mm (I was too busy watching the hot end to note the exact head position on the display)
Head stops (no lowering into print bed)
Terminal interface shows repeating list of the message:
Unknown command: "ª\x19\x10"

Systeminfo Bundle

browser.user_agent : Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/100.0.4896.127 Safari/537.36 OPR/86.0.4363.59
connectivity.connection_check :
connectivity.connection_ok : true
connectivity.enabled : false : true
connectivity.resolution_check :
connectivity.resolution_ok : true
env.hardware.cores : 4
env.hardware.freq : 1400
env.hardware.ram : 914006016
env.os.bits : 32 : linux
env.os.platform : linux
env.plugins.pi_support.model : Raspberry Pi 3 Model B Plus Rev 1.3
env.plugins.pi_support.octopi_version : 0.18.0
env.plugins.pi_support.octopiuptodate_build : 0.18.0-1.8.1-20220524101555
env.plugins.pi_support.throttle_state : 0x0
env.python.pip : 20.3.3
env.python.version : 3.7.3
env.python.virtualenv : true : 2022-05-25T09:11:42Z
octoprint.last_safe_mode.reason : settings
octoprint.safe_mode : true
octoprint.version : 1.8.1
systeminfo.generated : 2022-05-25T09:16:47Z
systeminfo.generator : systemapi

Additional information about your setup

This info above

A tiny hint:

So, what is odd?

First, I looked at the bundle and it was a zip. I clicked Advanced and saw it was system information in plain text which seemed to me more reasonable than expecting people to open a zip.

The oddity is that mone of my other Octoprints running on Pi with other printers, causes a reset on connection followed by connecting once the printer restarts;
And none of them causes a move up of hot end when they connect.

Furthermore, none of them causes unknown gibberish commands to be sent.
Is that not odd enough?

The zip contains WAY more information than the plain text, and we have a viewer specifically built for viewing these zips at

So please, share the bundle. (40.4 KB)

Seems there is no solution. Time to give up.

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