Fortimanager -ZTP first installation - purge

Hello,

I am setting up the ZTP function on the fortimanager.
After adding the firewall on fortimanager via the "add device" function
The firewall registers on the fortimanager (via the DHCP option)
The registration is done well, but during the 1st installation wizard the fortimanager generates a purge action which generates an install failed
Do you know why the fortimanager does this and do you know how to prevent this purge? Should I disable a function?
Below are the installation logs

Starting log (Run on device)
Start installing
FGT80E $ config endpoint-control fctems
FGT80E (fctems) $ purge
5 can not be deleted because it is a static entry.
4 can not be deleted because it is a static entry.
3 can not be deleted because it is a static entry.
2 can not be deleted because it is a static entry.
1 can not be deleted because it is a static entry.
FGT80E (fctems) $ end
FGT80E $ config user fortitoken
FGT80E (fortitoken) $ purge
FGT80E (fortitoken) $ end

---> generating verification report
<--- done generating verification report

------- Start to retry --------

FGT80E $ config endpoint-control fctems
FGT80E (fctems) $ purge
5 can not be deleted because it is a static entry.
4 can not be deleted because it is a static entry.
3 can not be deleted because it is a static entry.
2 can not be deleted because it is a static entry.
1 can not be deleted because it is a static entry.
FGT80E (fctems) $ end
---> generating verification report
<--- done generating verification report
install failed