PKHeX Opening for Let's Go, can't change it to SW/SH

[invinso1]

Hey there, I've just downloaded the newest version of PKHeX and when I open it, it opens as [PKHeX (Let's Go Pikachu!)] but I want to use it for SW/SH, and there appears to be no option to change the game version. In the pokemon editor itself, it enables me to change the version of the game between Let's Go Pikachu, Let's Go Eevee and GO only. I used to use PKHeX for USUM with no worries. Super confused as to why it's downloading Let's Go version with no option to switch games. Any help would be appreciated. Thanks!

[ReignOfComputer]

Options > Settings > Blank Save Version.

Or just load a save from the desired version.