BootIt2 not using BootIt boot after swapping SSD from one laptop to another identical one - Why ?

[Mrx]

I just changed out an SSD from one UEFI laptop to another identical one - only difference was old one had extra 2nd SSD internally.

It boots fine, but but on original it went to BIBM, only new one it goes straight into Win boot.

I would expect the new laptop to still boot into BIBM, given same disk.

Know how to easily it is to re-enable it by just re-installing/re-activation BootIt, but I want to undestand why it's not working automatically, given it's the exct same disk, in identical machine (aside from another SSD which I didn't swap)

What special-sauce does re-installing /re-activating Booit do, which a simple disk swap doesn't have already ?

Just trying to understand it.

[Mrx]

Disk is GPT partition style

[TeraByte Support]

If it was booting BIBM, it wasn't booting in UEFI mode.

[Mrx]

It was BIUEFI

[TeraByte Support]

reinstall it.

[Mrx]

I know re-installing it will make it work again, but was interested in why it doesn't work - ie. what does re-installing/re-activating actually do under-the-hood ?