Hi,
First of all, reset escalation is in 99% cases triggered by unserved SWT.
There is by default 15resets set in reset escalation. Your watchdog (SWT) is by default 20ms. After 20ms it must be either serviced, configured or disabled. If not, then after 300ms (15x 20ms) you will get reset escalation (permanent reset).
To see if your board is in reset escalation or it is in permanent reset at all you have to:
Take a scope and measure reset pin (resetb) after power on reset.
If the reset toggles you are in reset escalation.
If the reset is permanent right after power on reset you are in censored mode, secure or you have an ECC fault in HSM flash block (which is considered as side attack - bricked micro)
Share with us the power up sequence measurement, so we can guide you further.
regards,
Peter