Unable to Override - Silent Strike Only?

[CindyK_JA]

I've done all the cauldrons available prior to the end game. Have completed all the associated override 'repairs' at the Base.
I am able to override some machines (so far successful with 6 types) but others, I only get the 'silent strike' prompt (rather than the override prompt). I had this with the Bristleback during a salvage quest but I went to another location and the override worked.

I'm sneaking up behind them and remaining undetected.. am I missing something?

Anyone else having inconsistencies with this? Seems like I should be able to override almost anything at this point...

Thanks in advance...

[Theta]

Apex machines cant be overridden. Guessing it was one of those.

[CindyK_JA]

I just figured that out! You can't find an Apex when you need one and then, that's all I can find when I start experimenting! Thanks for the confirmation!