Unable to boot on fastboot/recovery

hi all,

1 / Flash PostMarketOS

I have flashed my FP4 boot partition with pmOS boot img stable repo.
Erase dtbo partition _a and _b.

https://images.postmarketos.org/bpo/v23.12/fairphone-fp4/phosh/20240327-0036/20240327-0036-postmarketOS-v23.12-phosh-22.3-fairphone-fp4-boot.img.xz

This image is flashed on boot_a and boot_b.

Flashed userdata partition with pmbootstrap to have PostmarketOS stable version.

After some trying pmbootstrap command, i decide to reflash all part to ROM stock.

2 / Back to ROM Stock

I flashed l part with your script to return back to stock. With .sh script on fairphone website.

https://fairphone-android-builds.ams3.digitaloceanspaces.com/FP4/A11/FP4-FP4K-factory.zip

I have notice with power + volume up or power + volume down, it’s impossible to boot at startup on fastbootd or recovery.

3 / PostmarketOS flash with pmbootstrap

I have reflashed the same file as linked up to boot on PosmarketOS.

But now, i can boot on PostmarketOS stable version but unable to boot on fastbootd or recovery.
So, impossible to flash PosmarketOS on edge version with pmbootstrap from computer to flash userdata.

4 / Solutions ?

-Boot on microSD if possible and flash somethings.
-Return the phone to Fairphone support

Thanks a lot