GIMP Version: 2.10.14
Operating System: Windows
GIMP Experience: New User

---

With each new opening of Gimp, brush tool, the dynamics are on Track Direction, which does not suit me. I put it on "Pressure Opacity" then I go in Edit / Preferences / Options of the tools and I click on "Save now tool options "and I validate.
Then I quit Gimp and reopen it. And it's still "Track Direction"!

For Gimp 2.10

Make sure the toolbox is set up the way you want to start.
Dynamic option (Dynamics Off is good)
Brush type and size and any other options
Font and size
FG / BG colours
Any of the other tools and their options

Back onto the tool you want Gimp to start with

then in Edit -> Preferences

Tool Options
Untick 'Save tool options on exit' Click on Save Tool Options Now'

Input Devices (this is where it differs from Gimp 2.8)
Untick 'Save input device settings on exit' Click on 'Save Input Device Settings Now'

OK the Preferences dialog. Restart Gimp.

Thank rich2005
it's this last step:
"Input Devices/Untick 'Save input device settings on exit' Click on 'Save Input Device Settings Now'
who saved me!