PhoenixFire: Thanks for the tip, will try that! Still strange though as in the Settings tab the correct custom path is also set. So technically it should override it with the same path, yet it defaults to the standard one?

Armory used to work on my PC, using the E:/Bitcoin (set under Settings) path and run Bitcoin Core manually when I need to update the node DB. The E:/Bitcoin side is over 500GB now.

There was also a smaller node DB in the standard location (under Appdata) from an old Bitcoin Core installation. It was not being updated and had around 70GB of DB data there, several years old.

I manually deleted it and (I believed) I did not need it. But for some reason it seems Armory still needed something to be in there (though an empty folder will not do), even if it was otherwise reading the correct data from E:/Bitcoin. Weird.