Apex Blue has replaced default theme for new layouts in existing files

[Peter Wagemans 3]

Can anyone acknowledge/confirm? I notice some strange behaviour with FileMaker 19.1.2 and also in 19.2…

I have these files that are already hosted for years on FileMaker Server, gradually evolving from 7 to 19. Over the years those respective files got their own theme, and until now the behaviour was something like: "use the last used theme" or something. So for new layouts, I get Minimalist or the custom theme of the file. Now all of a sudden, I get this butt ugly (sorry) Apex Blue theme on new layouts, and it is very annoying.

I probably have to take the files locally and force some new defaults in them, but anyone having experience with this?