2018 MBP Boot Loop - Unable to Verify Startup Disk

[ascender]

I seem to be stuck in a bit of a loop with a laptop following Catalina upgrade.

Someone has rebuilt the laptop with a fresh install of High Sierra which is presumably the version it came with. I couldn't install Catalina from the App Store as it was unable to verify the version. I've since been able to install it from a bootable USB stick after disabling the boot security.

Having now re-enabled the boot security options, the laptop won't boot - I get "unable to verify startup disk".

If I disable the boot security, the machine works fine, but that's obviously not ideal or a fix.

Any idea what I can do here?

Thanks!

 

[me55]

When you re-enable the boot security, is the Mac connected to WiFi? It needs an internet connection as far as I know to verify the current system with Apple as soon as you enable the boot security.

 

[ascender]

Yes, have tried with wifi and ethernet connected to make sure its definitely got a connection.

 

[Fishrrman]

I'd turn off the "boot security options" and LEAVE THEM turned off.
In fact, that's what I do with my own Mac Mini that has the t2 chip inside.
I want to be able to boot from ANY source at ANY time.

 

[ascender]

I'd turn off the "boot security options" and LEAVE THEM turned off.
In fact, that's what I do with my own Mac Mini that has the t2 chip inside.
I want to be able to boot from ANY source at ANY time.

I thought about doing that, but I'm wondering if this is symptomatic of a faulty T2 chip which could come back and bite me in the future if it totally craps out!