Hello Silverhead,
First of all I must thank you for your answer and your valuable advice.
I confirm your analysis, they are indeed presets or rather corrupted addresses.
According to your methodology, I performed a system reset ( FS9/FS10 ) and the Helix/LT has recovered the reason !
I did not know all repair procedures because the instructions for use of the Helix/LT is not complete ( Version 2.10 ).
Line 6 should make the effort to update its documentation because since 2016 the material has evolved.
I don’t know how to thank you for your help.
I appreciated your competence.
Best regards
Mike