Currently I’ve only one simple explanation for this issue: your GP button don’t work properly anymore, it seems that the contacts are defective.
E.g. you are writing “often the pressing+holding the GP button also gives you some note”
This indicates, that the GP button function has been triggered twice.
Are you using the 612-TL1100 switches from Mouser?
I’m using the same (with Wilba’s Frontpanel), and after some years and a lot of usage some buttons behaved erratic, so that I replaced them completely. It was a lot of work to desolder the buttons, but it was just necessary.
You can doublecheck the need for a replacement the following way:
Edit the MBSEQ_HW.V4 file with the MIOS Studio Filebrowser.
Add a # before each BUTTON_GP* parameter to disable the button assignments:
# SR Pin
#BUTTON_GP1 M5 0
#BUTTON_GP2 M5 1
#BUTTON_GP3 M6 0
#BUTTON_GP4 M6 1
#BUTTON_GP5 M7 0
#BUTTON_GP6 M7 1
#BUTTON_GP7 M8 0
#BUTTON_GP8 M8 1
#BUTTON_GP9 M4 0
#BUTTON_GP10 M4 1
#BUTTON_GP11 M3 0
#BUTTON_GP12 M3 1
#BUTTON_GP13 M2 0
#BUTTON_GP14 M2 1
#BUTTON_GP15 M1 0
#BUTTON_GP16 M1 1
store the file.
Thereafter enter “reset” in the MIOS terminal to take over the new configuration.
After reboot press the GP buttons and check the messages in the terminal.
E.g. pressing the GP1 button should only show a single:
[718809.425] [SEQ_UI_Button_Handler] Button SR:28, Pin:0 not mapped, it has been pressed.
and depressing the button should show:
[718809.969] [SEQ_UI_Button_Handler] Button SR:28, Pin:0 not mapped, it has been depressed.
If you get multiple messages, you know that the button needs replacement.
Or alternatively work with the SELECT button in future (because it seems to work reliable at your side).
Note: after this experiment, remove the “#” characters before the BUTTON_GP* parameters to undo the changes.
Best Regards, Thorsten.