lfs_mkdir fails after fresh format + mount ... and works after a reset

[jacquessamoun]

Hello,

starting off from a fully erased Flash (64 Mb), one of my very first application tasks is to create a directoty hierarchy.
So i am doing:
if ((status = lfs_mount(&pctx->lfs, &local_cfg)) != LFS_ERR_OK)
{
// Format it first
status = lfs_format(&pctx->lfs, &local_cfg);
status += lfs_mount(&pctx->lfs, &local_cfg);
}
Then:
int errno = lfs_mkdir(&pctx->lfs, "files");
if (errno != LFS_ERR_EXIST && errno != LFS_ERR_OK) {
return PLATFORM_ERROR_OPEN;
}

At the very first run of the app, i will invariably get an errno == LFS_ERR_IO, then the code is exiting.
However, after a reset, the lfs_mkdir would always succeed ....

Is there anything elase i should do after format/mount so that my lfs_mkdir would succeed first place ?
Thanks
Jacques

PS: my platform is iMXRT1176 based, the flashs are QSPI interfaced, and the code itself is running out of the same flash (different location, XIP)