Hi @Martin16v ,
Devices with Android 9 or higher will automatically enable file-based encryption if it has a PIN, pattern, or password set up. During the boot process, the phone will display "Phone is starting..." and the screen may be blank for a few seconds while encryption is taking place. However, if you feel it takes too long for your phone to start, you can disable the encryption to cut a few seconds off of the boot time.
I hope that this helps.